Washington DC Standards
DC.5.5. Physical Science: Broad Concept: Energy and matter have multiple forms and can be changed from one form to another. As a basis for understanding this concept, students:
5.5.1. Recognize that all matter is made of small particles called atoms, which are too small to see with our eyes; describe how atoms may combine to form molecules or crystalline solids (compounds).
5.5.2. Recognize that there are more than 100 different kinds of atoms (each called an element), which are displayed on the periodic table of the elements.
5.5.3. Explain that all matter is made up of an element, a compound, or mixtures of elements and compounds.