Across
- 2. an arrangement of elements arranged by there atomic number
- 7. a substance that cannot be broken down into simpler substances
- 8. The sum of the number of protons and neutrons in the nucleus of an element
Down
- 1. a characteristic of an substance that does not involve a chemical change
- 3. A charged particle that forms when gains or loses more than one electron
- 4. region around the nucleus where electrons are most likely to be found
- 5. abbreviation for a name of an element
- 6. the number of protons in an element