Across
- 3. with a positive 1 charge
- 5. the elements are arranged by increasing atomic number and by changes in physical and chemical properties
- 9. uses the symbol of the element and dots to represent the electrons in the outer energy level
- 12. area around the nucleus of an atom where its electrons are most likely found
- 13. protons and neutrons are made of even smaller particles called what?
- 14. the vertical columns in the periodic table
- 15. atoms of the same element that have different numbers of neutrons. (different mass numbers)
Down
- 1. particles with a negative 1 charge
- 2. the number of protons in the element
- 4. the weighted-average mass of the mixture of its isotopes
- 6. small positively charged center of the atom. contains the protons and neutrons
- 7. the sum of the protons and the neutrons in the element
- 8. the horizontal rows in the periodic table
- 10. the smallest piece of matter that still retains the properties of the element
- 11. neutral particles that have 0 charge