periodic table

2. An expression that shows the elements in a compound and the proportions of those elements.
5. The averaged number of protons and neutrons in an element.
9. The vertical columns on the periodic table
11. The man-made or laboratory made elements on the periodic table.
12. Forms of the same element that contain equal numbers of protons but different numbers of neutrons in the nucleus.
15. Organizes all discovered elements into rows (periods) and columns (groups) according to increasing atomic number.
17. The horizontal rows on the periodic table.
18. The number of protons in an element.
19. An atom or molecule with a net charge due to the loss or gain of one or more electrons.

1. The material involved in the change is structurally the same before and after the change.
3. An element whose properties are between those of metals and solid nonmetals or semiconductors.
4. A process that involves rearrangement of the molecular or ionic structure of a substance.
6. The positively charged subatomic particles in the nucleus of an atom.
7. A change of materials into another, new materials with different properties and one or more than one new substances are formed.
8. Electron in the outer shell of an atom.
10. Metals have a shiny appearance, are good conductors of heat and electricity, can be melted, are malleable and ductile.
13. Made of one type of atom, cannot be separated
14. The neutrally (no charge) subatomic particle in the nucleus of an atom.
16. a type of chemical element that lacks the charistics of a metal