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