Across
- 3. an arrangement of the elements showing the repeating pattern of their properties
- 4. a tiny, negatively charged particle that moves around the outside of the nucleus of an atom
- 5. the number of protons in the nucleus of an atom
- 6. the central core of an atom which contains protons and neutrons
- 8. the average mass of all the isotopes of an element
- 9. small, positively charged particles that are found in the nucleus of an atom
Down
- 1. a small particle in the nucleus of the atom, with no electrical charge
- 2. a one or two letter representation of an element
- 3. a horizontal row of elements in the periodic table
- 7. elements in the same vertical column of the periodic table; also called a family