isotope/_includes/element-partial.html

    <div class="element {% for cat in element.categories %}{{ cat }} {% endfor %} {% if page.infinite_scroll %} width2 height2 {% endif %}" data-symbol="{{ element.symbol }}" data-category="{{ element.categories[0] }}">
      <p class="number">{{ element.number }}</p>
      <h3 class="symbol">{{ element.symbol }}</h3>
      <h2 class="name">{{ element.name }}</h2>
      <p class="weight">{{ element.weight }}</p>
    </div>