Explanation:
Atoms can join together - they form bonds together - to make MOLECULES. ... For example, a hydrogen atom forms one bond, an oxygen atom forms two, and carbon forms four bonds. Look at that molecule of water again - each hydrogen has one bond, and the oxygen in the middle has two bonds. Molecules can be much bigger.
Ionization Energy: DOWN a Group: Ionization energy DECREASES as you go DOWN a Group because the farther the valence electrons are from the nucleus (pulling power of the protons) the less energy it costs another atom to steal them