Across
- 2. a formation when an atom loses or gains one or more electrons.
- 6. less reactive than an Alkali Metal and are known to be earth metals.
- 11. a metal that is less reactive and remain unchanged and are the earliest among metals.
- 13. elements in Group 18 that never react with other elements.
- 15. when an electron is added to the original atom.
- 16. a series of radioactive elements ,90-103,that are separated from the rest of the periodic table.
- 19. a column in the periodic table that is read top to bottom.
- 20. when an electron is lost from the atom and there are more protons than electrons.
- 21. a metal that is very reactive, to oxygen and water vapor, and belongs in Group 1.
- 23. elements that conduct electricity and heat well and have a shiny appearance.
- 24. a measure of atomic mass in an element.
Down
- 1. a negatively charged particle.
- 3. an uncharged particle.
- 4. elements that have properties of both metals and nonmetals.
- 5. the center of an atom.
- 7. a positively charged particle.
- 8. a row in the periodic table that is read left to right.
- 9. elements in Group 17 that are very reactive nonmetals that easily form compounds called salts with many metals.
- 10. when the identity of the atom changes due to the number of protons changing to create a new elements.
- 12. a crowd of electrons moving around the nucleus.
- 14. a series of metallic elements ,58-71,that are separated from the rest of the periodic table.
- 17. an element with a dull surface and are poor conductors of electricity and heat, opposite of a metal.
- 18. when atoms produce energy and particles from the nuclei to create new atoms of different elements.
- 21. the number of protons in the nucleus of the element.
- 22. atoms of the same element that have a different number of neutrons.
