Across
- 4. The layers or shells of electrons are referred to as being at different energy levels.
- 5. The arrangement of electrons in the shells or levels around the nucleus of an atom.
- 6. The elements found in Group 7 of the Periodic Table.
- 7. A table of all the elements placed in order of their atomic number.
- 9. The elements found in Group 8 of the Periodic Table.
Down
- 1. Forces of attraction between particles with opposite electrical charges.
- 2. Metals in Group 1 of the Periodic Table that produce alkalis when they react with water.
- 3. The layers of electrons arranged around the nucleus of an atom.
- 8. The number of protons in an atom; each type of atom has a unique atomic number.