<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Pure Element vs Pure Compound</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background-color: #f8f9fa;
      color: #1e2945;
      padding: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100vh;
    }

    .container {
      width: 100%;
      max-width: 680px;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .grid-container {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 12px;
      width: 100%;
    }

    @media (max-width: 520px) {
      .grid-container {
        grid-template-columns: 1fr;
        gap: 12px;
      }
    }

    .substance-box {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
    }

    .title {
      font-size: 15px;
      font-weight: 700;
      color: #1e2945;
      text-align: center;
      line-height: 1.2;
    }

    .formula {
      font-size: 12px;
      font-weight: 600;
      color: #64748b;
      margin-top: 2px;
      margin-bottom: 8px;
      text-align: center;
    }

    .chamber {
      width: 100%;
      height: 180px;
      background: #f1f5f9;
      border-radius: 8px;
      position: relative;
      overflow: hidden;
      border: 1px solid #cbd5e1;
    }

    .badge {
      margin-top: 10px;
      background-color: #ecfdf5;
      border: 1px solid #a7f3d0;
      color: #047857;
      font-size: 12px;
      font-weight: 700;
      padding: 5px 12px;
      border-radius: 9999px;
      display: inline-flex;
      align-items: center;
      gap: 5px;
      text-align: center;
      white-space: nowrap;
    }

    .badge svg {
      width: 14px;
      height: 14px;
      flex-shrink: 0;
    }

    .legend {
      display: flex;
      justify-content: center;
      gap: 16px;
      font-size: 11px;
      font-weight: 600;
      color: #475569;
      margin-top: 4px;
      flex-wrap: wrap;
    }

    .legend-item {
      display: flex;
      align-items: center;
      gap: 5px;
    }

    .dot {
      width: 10px;
      height: 10px;
      border-radius: 50%;
      display: inline-block;
    }

    .dot-teal { background: #0f766e; }
    .dot-purple { background: #581c87; }
    .dot-red { background: #b91c1c; }

    /* Subtle Gentle Floating Animations */
    @keyframes floatA {
      0%, 100% { transform: translate(0, 0); }
      50% { transform: translate(1.5px, -2px); }
    }

    @keyframes floatB {
      0%, 100% { transform: translate(0, 0); }
      50% { transform: translate(-2px, 1.5px); }
    }

    @keyframes floatC {
      0%, 100% { transform: translate(0, 0); }
      50% { transform: translate(1.5px, 2px); }
    }

    .drift-a { animation: floatA 5s ease-in-out infinite; }
    .drift-b { animation: floatB 6s ease-in-out infinite; }
    .drift-c { animation: floatC 5.5s ease-in-out infinite; }

    svg.chamber-svg {
      width: 100%;
      height: 100%;
      display: block;
    }
  </style>
</head>
<body>

  <div class="container">
    <div class="grid-container">
      
      <div class="substance-box">
        <div class="title">Pure Element (Argon)</div>
        <div class="formula">12 Single Atoms (Ar)</div>
        
        <div class="chamber">
          <svg class="chamber-svg" viewBox="0 0 240 180" aria-label="12 identical teal Argon atoms">
            <defs>
              <radialGradient id="tealGrad" cx="35%" cy="35%" r="65%">
                <stop offset="0%" stop-color="#2dd4bf" />
                <stop offset="100%" stop-color="#0f766e" />
              </radialGradient>
            </defs>

            
            <g class="drift-a"><circle cx="38" cy="32" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
            <g class="drift-b"><circle cx="115" cy="26" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
            <g class="drift-c"><circle cx="192" cy="36" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
            <g class="drift-b"><circle cx="72" cy="68" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
            <g class="drift-a"><circle cx="152" cy="66" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
            <g class="drift-c"><circle cx="32" cy="105" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
            <g class="drift-a"><circle cx="112" cy="110" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
            <g class="drift-b"><circle cx="204" cy="100" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
            <g class="drift-c"><circle cx="62" cy="148" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
            <g class="drift-a"><circle cx="158" cy="142" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
            <g class="drift-b"><circle cx="210" cy="152" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
            <g class="drift-c"><circle cx="125" cy="158" r="9" fill="url(#tealGrad)" stroke="#115e59" stroke-width="1.2"/></g>
          </svg>
        </div>

        <div class="legend">
          <span class="legend-item"><span class="dot dot-teal"></span> Argon (Ar)</span>
        </div>

        <div class="badge">
          <svg viewBox="0 0 20 20" fill="currentColor">
            <path fill-rule="evenodd" d="M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z" clip-rule="evenodd"/>
          </svg>
          100% Identical Units = Pure
        </div>
      </div>

      
      <div class="substance-box">
        <div class="title">Pure Compound (Carbon Dioxide)</div>
        <div class="formula">8 Bound Molecules (CO₂)</div>
        
        <div class="chamber">
          <svg class="chamber-svg" viewBox="0 0 240 180" aria-label="8 identical Carbon Dioxide molecules">
            <defs>
              <radialGradient id="purpleGrad" cx="35%" cy="35%" r="65%">
                <stop offset="0%" stop-color="#a855f7" />
                <stop offset="100%" stop-color="#581c87" />
              </radialGradient>
              <radialGradient id="redGrad" cx="35%" cy="35%" r="65%">
                <stop offset="0%" stop-color="#f87171" />
                <stop offset="100%" stop-color="#b91c1c" />
              </radialGradient>
              
              
              <g id="co2-molecule">
                <circle cx="-11.5" cy="0" r="6.8" fill="url(#redGrad)" stroke="#7f1d1d" stroke-width="1"/>
                <circle cx="11.5" cy="0" r="6.8" fill="url(#redGrad)" stroke="#7f1d1d" stroke-width="1"/>
                <circle cx="0" cy="0" r="7.8" fill="url(#purpleGrad)" stroke="#3b0764" stroke-width="1.1"/>
              </g>
            </defs>

            
            <g transform="translate(48, 32) rotate(-15)">
              <g class="drift-a"><use href="#co2-molecule"/></g>
            </g>

            <g transform="translate(182, 34) rotate(20)">
              <g class="drift-b"><use href="#co2-molecule"/></g>
            </g>

            <g transform="translate(116, 64) rotate(-35)">
              <g class="drift-c"><use href="#co2-molecule"/></g>
            </g>

            <g transform="translate(42, 94) rotate(40)">
              <g class="drift-b"><use href="#co2-molecule"/></g>
            </g>

            <g transform="translate(196, 90) rotate(-20)">
              <g class="drift-a"><use href="#co2-molecule"/></g>
            </g>

            <g transform="translate(122, 122) rotate(15)">
              <g class="drift-c"><use href="#co2-molecule"/></g>
            </g>

            <g transform="translate(52, 150) rotate(-10)">
              <g class="drift-a"><use href="#co2-molecule"/></g>
            </g>

            <g transform="translate(185, 148) rotate(35)">
              <g class="drift-b"><use href="#co2-molecule"/></g>
            </g>
          </svg>
        </div>

        <div class="legend">
          <span class="legend-item"><span class="dot dot-purple"></span> Carbon (C)</span>
          <span class="legend-item"><span class="dot dot-red"></span> Oxygen (O)</span>
        </div>

        <div class="badge">
          <svg viewBox="0 0 20 20" fill="currentColor">
            <path fill-rule="evenodd" d="M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z" clip-rule="evenodd"/>
          </svg>
          100% Identical Units = Pure
        </div>
      </div>
    </div>
  </div>

</body>
</html>

Particle Model of Pure Substances vs Mixtures

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      width: 100%;
      height: 100%;
      background: #ffffff;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      display: flex;
      align-items: center;
      justify-content: center;
      padding: 12px;
      overflow: hidden;
    }
    .diagram-svg {
      width: 100%;
      max-width: 600px;
      height: auto;
      display: block;
    }
    .title-main {
      font-size: 15px;
      font-weight: 700;
      fill: #1e2945;
      text-anchor: middle;
    }
    .title-sub {
      font-size: 12px;
      font-weight: 500;
      fill: #64748b;
      text-anchor: middle;
    }
    .beaker {
      fill: #f8fafc;
      stroke: #cbd5e1;
      stroke-width: 2;
      rx: 16px;
      ry: 16px;
    }
    .divider {
      stroke: #e2e8f0;
      stroke-width: 2;
      stroke-dasharray: 6 6;
    }
    .p-blue {
      fill: #0284c7;
      stroke: #0369a1;
      stroke-width: 1.5;
    }
    .p-orange {
      fill: #ea580c;
      stroke: #c2410c;
      stroke-width: 1.5;
    }
    .layer-line {
      stroke: #cbd5e1;
      stroke-width: 1.5;
      stroke-dasharray: 4 4;
    }
  </style>
</head>
<body>
  <svg class="diagram-svg" viewBox="0 0 600 420" xmlns="http://www.w3.org/2000/svg">
    
    <line x1="300" y1="16" x2="300" y2="404" class="divider" />

    
    <g id="homogeneous-panel">
      <text x="150" y="32" class="title-main">Homogeneous Mixture</text>
      <text x="150" y="52" class="title-sub">Evenly Mixed</text>

      
      <rect x="30" y="70" width="240" height="320" class="beaker" />

      
      
      <circle cx="58" cy="105" r="11" class="p-blue" />
      <circle cx="104" cy="105" r="11" class="p-orange" />
      <circle cx="150" cy="105" r="11" class="p-blue" />
      <circle cx="196" cy="105" r="11" class="p-orange" />
      <circle cx="242" cy="105" r="11" class="p-blue" />

      
      <circle cx="58" cy="155" r="11" class="p-orange" />
      <circle cx="104" cy="155" r="11" class="p-blue" />
      <circle cx="150" cy="155" r="11" class="p-orange" />
      <circle cx="196" cy="155" r="11" class="p-blue" />
      <circle cx="242" cy="155" r="11" class="p-orange" />

      
      <circle cx="58" cy="205" r="11" class="p-blue" />
      <circle cx="104" cy="205" r="11" class="p-orange" />
      <circle cx="150" cy="205" r="11" class="p-blue" />
      <circle cx="196" cy="205" r="11" class="p-orange" />
      <circle cx="242" cy="205" r="11" class="p-blue" />

      
      <circle cx="58" cy="255" r="11" class="p-orange" />
      <circle cx="104" cy="255" r="11" class="p-blue" />
      <circle cx="150" cy="255" r="11" class="p-orange" />
      <circle cx="196" cy="255" r="11" class="p-blue" />
      <circle cx="242" cy="255" r="11" class="p-orange" />

      
      <circle cx="58" cy="305" r="11" class="p-blue" />
      <circle cx="104" cy="305" r="11" class="p-orange" />
      <circle cx="150" cy="305" r="11" class="p-blue" />
      <circle cx="196" cy="305" r="11" class="p-orange" />
      <circle cx="242" cy="305" r="11" class="p-blue" />

      
      <circle cx="58" cy="355" r="11" class="p-orange" />
      <circle cx="104" cy="355" r="11" class="p-blue" />
      <circle cx="150" cy="355" r="11" class="p-orange" />
      <circle cx="196" cy="355" r="11" class="p-blue" />
      <circle cx="242" cy="355" r="11" class="p-orange" />
    </g>

    
    <g id="heterogeneous-panel">
      <text x="450" y="32" class="title-main">Heterogeneous Mixture</text>
      <text x="450" y="52" class="title-sub">Unevenly Clumped</text>

      
      <rect x="330" y="70" width="240" height="320" class="beaker" />

      
      <line x1="330" y1="245" x2="570" y2="245" class="layer-line" />

      
      <circle cx="365" cy="110" r="11" class="p-blue" />
      <circle cx="445" cy="100" r="11" class="p-blue" />
      <circle cx="525" cy="115" r="11" class="p-blue" />
      <circle cx="400" cy="148" r="11" class="p-blue" />
      <circle cx="490" cy="155" r="11" class="p-blue" />
      <circle cx="360" cy="190" r="11" class="p-blue" />
      <circle cx="445" cy="200" r="11" class="p-blue" />
      <circle cx="530" cy="180" r="11" class="p-blue" />
      <circle cx="395" cy="230" r="11" class="p-blue" />
      <circle cx="485" cy="225" r="11" class="p-blue" />

      
      
      <circle cx="365" cy="270" r="11" class="p-orange" />
      <circle cx="395" cy="268" r="11" class="p-orange" />
      <circle cx="425" cy="272" r="11" class="p-orange" />
      <circle cx="455" cy="267" r="11" class="p-orange" />
      <circle cx="485" cy="271" r="11" class="p-orange" />
      <circle cx="515" cy="268" r="11" class="p-orange" />
      <circle cx="545" cy="273" r="11" class="p-orange" />

      
      <circle cx="350" cy="300" r="11" class="p-orange" />
      <circle cx="380" cy="298" r="11" class="p-orange" />
      <circle cx="410" cy="302" r="11" class="p-orange" />
      <circle cx="440" cy="297" r="11" class="p-orange" />
      <circle cx="470" cy="301" r="11" class="p-orange" />
      <circle cx="500" cy="298" r="11" class="p-orange" />
      <circle cx="530" cy="302" r="11" class="p-orange" />

      
      <circle cx="360" cy="332" r="11" class="p-orange" />
      <circle cx="390" cy="330" r="11" class="p-orange" />
      <circle cx="420" cy="334" r="11" class="p-orange" />
      <circle cx="450" cy="329" r="11" class="p-orange" />
      <circle cx="480" cy="333" r="11" class="p-orange" />
      <circle cx="510" cy="330" r="11" class="p-orange" />
      <circle cx="540" cy="334" r="11" class="p-orange" />

      
      <circle cx="375" cy="364" r="11" class="p-orange" />
      <circle cx="405" cy="362" r="11" class="p-orange" />
      <circle cx="435" cy="365" r="11" class="p-orange" />
      <circle cx="465" cy="361" r="11" class="p-orange" />
      <circle cx="495" cy="364" r="11" class="p-orange" />
      <circle cx="525" cy="362" r="11" class="p-orange" />
    </g>
  </svg>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="1:1">
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      width: 100%;
      min-height: 100%;
      font-family: system-ui, -apple-system, sans-serif;
      background: transparent;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: flex-start;
      padding: 10px;
      gap: 10px;
    }

    .grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 8px;
      width: 100%;
      max-width: 480px;
    }

    .cell {
      background: #f8fafc;
      border: 2px solid #e2e8f0;
      border-radius: 12px;
      padding: 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      cursor: pointer;
      user-select: none;
      transition: border-color 0.2s ease, box-shadow 0.2s ease;
    }

    .cell:hover {
      border-color: #94a3b8;
    }

    .cell.active {
      border-color: #22b7ff;
      box-shadow: 0 0 0 2px rgba(34, 183, 255, 0.25);
      background: #ffffff;
    }

    .title {
      font-size: 13px;
      font-weight: 700;
      color: #1e2945;
      margin-bottom: 4px;
      text-align: center;
      white-space: nowrap;
    }

    .box-svg {
      width: 100%;
      aspect-ratio: 1 / 1;
      max-height: 120px;
      background: #ffffff;
      border: 1px solid #cbd5e1;
      border-radius: 8px;
    }

    .pathway {
      width: 100%;
      max-width: 480px;
      background: #f8fafc;
      border-radius: 10px;
      border: 1px solid #e2e8f0;
      padding: 8px 12px;
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .path-row {
      display: flex;
      align-items: center;
      justify-content: space-between;
      font-size: 12px;
      font-weight: 600;
    }

    .badge {
      display: inline-flex;
      align-items: center;
      gap: 4px;
      padding: 3px 8px;
      border-radius: 6px;
      font-size: 12px;
      font-weight: 600;
      background: #e2e8f0;
      color: #475569;
    }

    .badge.highlight {
      background: #e0f2fe;
      color: #0284c7;
      border: 1px solid #bae6fd;
    }

    .arrow {
      color: #94a3b8;
      font-size: 11px;
    }
  </style>
</head>
<body>

  <div class="grid">
    
    <div class="cell active" id="c0" onclick="select(0)">
      <div class="title">Element</div>
      <svg class="box-svg" viewBox="0 0 100 100">
        
        <circle cx="25" cy="25" r="7" fill="#22b7ff" stroke="#0284c7" stroke-width="1.5"/>
        <circle cx="75" cy="22" r="7" fill="#22b7ff" stroke="#0284c7" stroke-width="1.5"/>
        <circle cx="50" cy="50" r="7" fill="#22b7ff" stroke="#0284c7" stroke-width="1.5"/>
        <circle cx="20" cy="75" r="7" fill="#22b7ff" stroke="#0284c7" stroke-width="1.5"/>
        <circle cx="80" cy="78" r="7" fill="#22b7ff" stroke="#0284c7" stroke-width="1.5"/>
      </svg>
    </div>

    
    <div class="cell" id="c1" onclick="select(1)">
      <div class="title">Compound</div>
      <svg class="box-svg" viewBox="0 0 100 100">
        
        
        <g transform="translate(25, 25)">
          <circle cx="0" cy="0" r="6" fill="#f87171" stroke="#dc2626" stroke-width="1.2"/>
          <circle cx="-5" cy="-5" r="3.5" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2"/>
          <circle cx="5" cy="-5" r="3.5" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2"/>
        </g>
        
        <g transform="translate(75, 25)">
          <circle cx="0" cy="0" r="6" fill="#f87171" stroke="#dc2626" stroke-width="1.2"/>
          <circle cx="-5" cy="5" r="3.5" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2"/>
          <circle cx="5" cy="5" r="3.5" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2"/>
        </g>
        
        <g transform="translate(50, 55)">
          <circle cx="0" cy="0" r="6" fill="#f87171" stroke="#dc2626" stroke-width="1.2"/>
          <circle cx="-6" cy="1" r="3.5" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2"/>
          <circle cx="1" cy="-6" r="3.5" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2"/>
        </g>
        
        <g transform="translate(25, 80)">
          <circle cx="0" cy="0" r="6" fill="#f87171" stroke="#dc2626" stroke-width="1.2"/>
          <circle cx="-5" cy="-5" r="3.5" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2"/>
          <circle cx="5" cy="-5" r="3.5" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2"/>
        </g>
        
        <g transform="translate(75, 80)">
          <circle cx="0" cy="0" r="6" fill="#f87171" stroke="#dc2626" stroke-width="1.2"/>
          <circle cx="6" cy="-1" r="3.5" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2"/>
          <circle cx="-1" cy="6" r="3.5" fill="#ffffff" stroke="#94a3b8" stroke-width="1.2"/>
        </g>
      </svg>
    </div>

    
    <div class="cell" id="c2" onclick="select(2)">
      <div class="title">Homogeneous</div>
      <svg class="box-svg" viewBox="0 0 100 100">
        
        <g transform="translate(20, 25)">
          <circle cx="-3" cy="0" r="4.5" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
          <circle cx="3" cy="0" r="4.5" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
        </g>
        <circle cx="65" cy="20" r="6" fill="#22b7ff" stroke="#0284c7" stroke-width="1.2"/>

        <circle cx="30" cy="55" r="6" fill="#22b7ff" stroke="#0284c7" stroke-width="1.2"/>
        <g transform="translate(75, 55)">
          <circle cx="0" cy="-3" r="4.5" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
          <circle cx="0" cy="3" r="4.5" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
        </g>

        <g transform="translate(30, 82)">
          <circle cx="-3" cy="0" r="4.5" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
          <circle cx="3" cy="0" r="4.5" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
        </g>
        <circle cx="75" cy="85" r="6" fill="#22b7ff" stroke="#0284c7" stroke-width="1.2"/>
      </svg>
    </div>

    
    <div class="cell" id="c3" onclick="select(3)">
      <div class="title">Heterogeneous</div>
      <svg class="box-svg" viewBox="0 0 100 100">
        
        <g transform="translate(20, 20)">
          <circle cx="-3" cy="0" r="4" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
          <circle cx="3" cy="0" r="4" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
        </g>
        <g transform="translate(42, 22)">
          <circle cx="0" cy="-3" r="4" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
          <circle cx="0" cy="3" r="4" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
        </g>
        <g transform="translate(22, 42)">
          <circle cx="-2" cy="-2" r="4" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
          <circle cx="2" cy="2" r="4" fill="#4ade80" stroke="#16a34a" stroke-width="1.2"/>
        </g>

        
        <circle cx="65" cy="65" r="5.5" fill="#22b7ff" stroke="#0284c7" stroke-width="1.2"/>
        <circle cx="85" cy="62" r="5.5" fill="#22b7ff" stroke="#0284c7" stroke-width="1.2"/>
        <circle cx="60" cy="85" r="5.5" fill="#22b7ff" stroke="#0284c7" stroke-width="1.2"/>
        <circle cx="82" cy="84" r="5.5" fill="#22b7ff" stroke="#0284c7" stroke-width="1.2"/>
      </svg>
    </div>
  </div>

  
  <div class="pathway">
    <div class="path-row">
      <span style="color:#64748b;">Step 1: Particle Types</span>
      <span class="badge highlight" id="s1">1 Type (Pure)</span>
    </div>
    <div class="path-row">
      <span style="color:#64748b;">Step 2: Structure</span>
      <span class="badge highlight" id="s2">1 Atom Type (Element)</span>
    </div>
  </div>

  <script>
    const data = [
      { s1: "1 Type (Pure)", s2: "1 Atom Type (Element)" },
      { s1: "1 Type (Pure)", s2: "Bonded Atoms (Compound)" },
      { s1: "Multiple Types (Mixture)", s2: "Uniform (Homogeneous)" },
      { s1: "Multiple Types (Mixture)", s2: "Clustered (Heterogeneous)" }
    ];

    function select(idx) {
      for (let i = 0; i < 4; i++) {
        document.getElementById('c' + i).classList.toggle('active', i === idx);
      }
      document.getElementById('s1').textContent = data[idx].s1;
      document.getElementById('s2').textContent = data[idx].s2;
    }
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <title>Particle Units</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      width: 100%;
      min-height: 100%;
      background: #ffffff;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 12px;
    }

    .main-grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      width: 100%;
      max-width: 600px;
    }

    @media (max-width: 480px) {
      .main-grid {
        grid-template-columns: 1fr;
      }
    }

    .panel {
      background: #f8fafc;
      border: 1px solid #e2e8f0;
      border-radius: 12px;
      padding: 12px;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .panel-title {
      font-size: 13px;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 0.5px;
      color: #64748b;
      text-align: center;
    }

    .particle-row {
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .particle-card {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 10px 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 6px;
      cursor: pointer;
      user-select: none;
      transition: background-color 0.2s ease, border-color 0.2s ease;
    }

    .particle-card:hover {
      background: #f1f5f9;
    }

    .particle-card.active {
      border-color: #0284c7;
      background: #f0f9ff;
    }

    .stage {
      height: 64px;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .unit-ring {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 6px;
      border-radius: 9999px;
      border: 2px dashed #94a3b8;
      background: rgba(241, 245, 249, 0.4);
      transition: border-color 0.25s ease, background-color 0.25s ease, box-shadow 0.25s ease;
    }

    .particle-card.active .unit-ring {
      border-color: #0284c7;
      background: rgba(2, 132, 199, 0.08);
      box-shadow: 0 0 12px rgba(2, 132, 199, 0.25);
    }

    /* Atoms */
    .atom {
      border-radius: 50%;
      flex-shrink: 0;
      box-shadow: inset -2px -2px 4px rgba(0, 0, 0, 0.2), inset 2px 2px 4px rgba(255, 255, 255, 0.6);
    }

    .atom-blue {
      background: radial-gradient(circle at 35% 35%, #38bdf8, #1d4ed8);
      width: 32px;
      height: 32px;
    }

    .atom-blue-small {
      background: radial-gradient(circle at 35% 35%, #38bdf8, #1d4ed8);
      width: 22px;
      height: 22px;
    }

    .atom-red {
      background: radial-gradient(circle at 35% 35%, #f87171, #b91c1c);
      width: 36px;
      height: 36px;
    }

    .diatomic-group {
      display: flex;
      align-items: center;
    }

    .diatomic-group .atom:nth-child(2) {
      margin-left: -6px;
    }

    .compound-group {
      display: flex;
      align-items: center;
      position: relative;
    }

    .compound-group .atom-blue-small:first-child {
      margin-right: -6px;
      z-index: 1;
    }

    .compound-group .atom-red {
      z-index: 2;
    }

    .compound-group .atom-blue-small:last-child {
      margin-left: -6px;
      z-index: 1;
    }

    .label {
      font-size: 13px;
      font-weight: 600;
      color: #1e2945;
      text-align: center;
    }

    .badge {
      font-size: 11px;
      font-weight: 700;
      padding: 3px 8px;
      border-radius: 12px;
      background: #e2e8f0;
      color: #475569;
      transition: background-color 0.25s ease, color 0.25s ease;
    }

    .particle-card.active .badge {
      background: #0284c7;
      color: #ffffff;
    }

    .banner {
      width: 100%;
      max-width: 600px;
      background: #f0fdf4;
      border: 1px solid #bbf7d0;
      border-radius: 8px;
      padding: 6px 12px;
      font-size: 13px;
      font-weight: 700;
      color: #166534;
      text-align: center;
    }
  </style>
</head>
<body>

  <div class="main-grid">
    
    <div class="panel">
      <div class="panel-title">Elements</div>
      <div class="particle-row">
        
        <div class="particle-card active" onclick="selectCard(this)">
          <div class="stage">
            <div class="unit-ring">
              <div class="atom atom-blue"></div>
            </div>
          </div>
          <div class="label">Single Atom</div>
          <span class="badge">1 Particle Unit</span>
        </div>

        <div class="particle-card active" onclick="selectCard(this)">
          <div class="stage">
            <div class="unit-ring">
              <div class="diatomic-group">
                <div class="atom atom-blue"></div>
                <div class="atom atom-blue"></div>
              </div>
            </div>
          </div>
          <div class="label">Diatomic Molecule</div>
          <span class="badge">1 Particle Unit</span>
        </div>

      </div>
    </div>

    
    <div class="panel">
      <div class="panel-title">Compound</div>
      <div class="particle-row">
        
        <div class="particle-card active" style="min-height: 154px; justify-content: space-around;" onclick="selectCard(this)">
          <div class="stage">
            <div class="unit-ring">
              <div class="compound-group">
                <div class="atom atom-blue-small"></div>
                <div class="atom atom-red"></div>
                <div class="atom atom-blue-small"></div>
              </div>
            </div>
          </div>
          <div class="label">Compound Molecule</div>
          <span class="badge">1 Particle Unit</span>
        </div>

      </div>
    </div>
  </div>

  <div class="banner">
    ✦ Bonded Group = 1 Independent Particle
  </div>

  <script>
    function selectCard(card) {
      card.classList.toggle('active');
    }
  </script>
</body>
</html>

What Is an Atom?

What Is a Molecule?

Elements: The Simplest Form of Matter

Compounds: Two or More Elements Combined

Comparing Elements and Compounds

science

Atoms, Molecules, Elements, and Compounds

实验室安全守则与药品危险标识辨认

块状固体与金属颗粒的取用操作

粉末状固体药品的取用与药匙纸槽使用

托盘天平的结构与固体药品称量规范

较多量液体药品的倾倒操作

胶头滴管的使用与微量液体取用

量筒量取液体与视线读数误差分析

化学药品的安全取用与定量量取规范

Single-Atom Elements vs. Molecular Elements

Chemical Symbols for Elements

Chemical Formulas for Compounds

Reading Subscripts in Chemical Formulas

Chemical Symbols and Formulas

Los ríos y el nacimiento de las primeras civilizaciones

Cuencas hidrográficas: estructura y captación de agua

Los páramos y bosques de niebla como fábricas de agua

Aguas subterráneas: acuíferos y recarga hídrica

Sistemas ancestrales y modernos de riego agrícola

Potabilización del agua: etapas y procesos de tratamiento

Distribución urbana y rural del agua: acueductos comunitarios

Vertimientos domésticos e industriales en fuentes hídricas

Eutrofización: acumulación de nutrientes en lagos y embalses

Gobernanza del agua y conservación comunitaria de microcuencas

El recurso hídrico, civilizaciones y gestión de cuencas

Explaining Density with Particle Theory

Explaining Compressibility with Particle Theory

Diffusion and Particle Theory

Particle Theory and Pressure in Gases

Using Particle Models to Explain Dissolving

Using Particle Models to Explain Conservation

Relating Particle Behaviour to Substance Properties

Investigating State Changes with Particle Models

Particle Theory: Explaining Substance Properties and Behaviours

Separating Mixtures Using Physical Properties

Identifying Elements by Their Proton Number

Using the Periodic Table to Identify Atoms in a Formula

Distinguishing Physical and Chemical Changes

Combining Elements to Form Diverse Compounds

Using Periodic Patterns to Predict Properties of Unknown Elements

Pure Substances, Mixtures, and the Periodic Table

固体的溶解操作与玻璃棒搅拌规范

液体与液体的混合技巧及浓硫酸稀释

固液反应混合现象观察与产物收集初步

配制一定溶质质量分数的溶液实验全过程

实验废液与药品残渣的安全收集与处置

物质溶解、混合与溶液配制综合实验

What Makes a Pure Substance?

Elements and Compounds as Pure Substances

What Is a Mixture?

Pure Substances and Mixtures

Introduction to the Periodic Table

Finding Elements on the Periodic Table

Counting Each Kind of Atom in a Formula

Comparing Formulas: Same Elements, Different Atom Counts

Interpreting Chemical Formulas in Real-World Contexts

The Periodic Table and Interpreting Chemical Formulas

粗盐提纯基本实验流程：溶解、过滤与蒸发

粗盐提纯中玻璃棒的四大作用与操作规范

粗盐提纯精盐产率计算与实验误差分析

物质分离与提纯实验实践：粗盐提纯与提纯拓展

Types of Mixtures: Solutions

Suspensions and Colloids

Solubility and Saturated Solutions

Concentration of Solutions

Types of Mixtures and Solutions

Clasificación general de la materia: sustancias puras y mezclas

Sustancias puras: elementos químicos y compuestos

Mezclas heterogéneas: fases y componentes visibles

Mezclas homogéneas: soluciones, soluto y solvente

Coloides y suspensiones: el efecto Tyndall

Clasificación de la materia: sustancias puras y mezclas

Separating Mixtures by Filtration

Separating Mixtures by Evaporation

Separating Mixtures by Distillation

Separating Mixtures by Chromatography

Separating Mixtures Using Magnets and Sieving

Choosing the Right Separation Method

Planning a Mixture Separation Investigation

Separating Mixtures

溶质质量分数的定义与配制所需质量计算

托盘天平与称量纸的规范使用与称量固体

量筒规格选择与液体的精确量取读数

烧杯中溶解固体与玻璃棒搅拌操作

溶液装瓶保存与试剂标签规范书写

溶液配制中的误差诊断与浓度偏大偏小分析

浓溶液稀释配制稀溶液的计算与操作

一定溶质质量分数溶液的配制

Identifying the Solute and Solvent in a Solution

Solutions vs. Nonsolution Mixtures

What Is an Aqueous Solution?

Water as the Universal Solvent

Solid, Liquid, and Gas Solutes in Aqueous Solutions

Comparing Dissolving vs. Not Dissolving

Introduction to Aqueous Solutions

Métodos de separación de mezclas

Tamizado y filtración en el laboratorio y el hogar

Decantación y separación magnética

Evaporación y cristalización: recuperación de solutos

Destilación simple: separación por puntos de ebullición

Cromatografía en papel: separación de pigmentos y tintas

Potabilización del agua: aplicación de métodos de separación

Diseño de un plan experimental para separar mezclas complejas

Métodos físicos de separación de mezclas

What Is Concentration?

Comparing Concentrated vs. Dilute Solutions

Making a More Concentrated Solution

What Is Dilution?

Diluting a Solution Step by Step

Calculating Simple Concentration Ratios

Comparing Different Types of Mixtures

Separating Solutions by Evaporation

Concentration and Dilution Word Problems

Concentration, Dilution, and Separation of Solutions

Filtración y tamizado: separación de sólidos y líquidos insolubles

Decantación y centrifugación: separación por diferencia de densidad

Evaporación y cristalización: obtención de solutos sólidos

Destilación simple y fraccionada: puntos de ebullición

Refinación del petróleo: destilación fraccionada industrial

Separación magnética e inmantación en la minería y reciclaje

Cromatografía: separación de pigmentos y sustancias colorantes

Tratamiento de aguas residuales: procesos físicos y químicos

Procesos industriales de extracción de aceites y esencias vegetales

Métodos de separación de mezclas y química industrial

What Affects How Fast a Solute Dissolves?

How Temperature Affects Dissolving

How Surface Area Affects Dissolution Rate

Crushing and Grinding: Increasing Surface Area for Faster Dissolving

How Agitation (Stirring) Affects Dissolution Rate

Comparing Factors: Which Affects Dissolution Rate Most?

Factors Affecting the Rate of Dissolution

Measuring Dissolution Time Accurately

Identifying Variables in a Dissolution Investigation

Designing Your Own Dissolution Rate Investigation

Recording and Graphing Dissolution Rate Data

Modeling Dissolution with Particle Diagrams

Predicting Dissolution Rates in New Situations

Investigating and Modeling Dissolution Rates

¿Qué son los ambientes extremos? Temperatura, presión, pH y salinidad

Termófilos e hipertermófilos: vida a altas temperaturas

La enzima Taq polimerasa: revolución biotecnológica de la PCR

Psicrófilos: microorganismos adaptados al frío extremo

Enzimas psicrófilas en detergentes y lavado ecológico en frío

Halófilos: arqueas y bacterias en ambientes hipersalinos

Acidófilos y biolixiviación bacteriana en la minería sostenible

Alcalófilos en la industria textil y fabricación de papel

Biorremediación microbiana: limpieza de derrames de petróleo

Biorreactores y producción industrial de biopolímeros sostenibles

Microorganismos extremófilos y biotecnología industrial

Elements vs. Compounds: What Makes Them Different

Atoms and Molecules in Elements and Compounds

Representing Elements and Compounds With Symbols and Formulas

Reading Subscripts and Coefficients in Chemical Formulas

Counting Atoms in Formulas With Parentheses

Comparing Element and Compound Structures

Building Molecular Models From Chemical Formulas

Elements, Compounds, and Chemical Formulas (Deep Dive)

Understanding Aqueous Solutions and Their Properties

Identifying Solute and Solvent in Everyday Solutions

Understanding Concentration in Aqueous Solutions

How Dilution Changes Solution Concentration

Comparing Concentrated and Dilute Solutions

Aqueous Solutions, Concentration, and Dilution

How Temperature Affects Dissolving Rate

How Surface Area Affects Dissolving Rate

How Stirring Affects Dissolving Rate

Comparing Factors That Affect Dissolution

Planning a Dissolution Rate Investigation

Particle Models of the Dissolving Process

Factors Affecting Dissolution Rates

OGS.8.PS.2

OGS.8.PS.2

Aligned learning resources

Related diagrams