Atoms, Elements, and Compounds

Understand that all substances are made of atoms and that an atom is the smallest part of an element.
Represent atoms of elements using chemical symbols (e.g., O, Na).
Identify elements in Groups 1 and 7, and the first 20 elements in the periodic table.
Describe how compounds are formed from elements by chemical reactions involving energy changes.
Represent chemical reactions using word equations and balanced symbol equations.
(HT only) Write balanced half equations and ionic equations where appropriate.

What you need to know