Chemistry

2. equivalent to the number of protons and neutrons in an element
4. formed by atoms or molecules by one or more electrons
5. short representation of a chemical element
8. determines chemical properties and place(on P.T) of an element
9. process accompanied by the absorption of heat
11. a thin coating of gold, silver, or another metal
12. horizontal rows on the periodic table
17. examples: helium, radon, xenon, krypton, neon, and argon
18. substances consumed during the reaction to make product
19. chemical element with properties in between those of metals and nonmetals
20. basic unit of a chemical element
21. electrons on the outside rings
23. consists of several parts, or elements in particular
26. on the periodic table there are 18 of these

1. principle in any closed system subjected to no external forces, mass is irrespective of changes in form
3. particle with a negative charge
6. element of substance that does not conduct electricity
7. particle with no charge
10. conductors of electricity, have crystalline solids with a metallic luster, and have a high chemical reativity
13. developed periodic table and predicted discovery of several new elements
14. group of atoms bonded together
15. process accompanied by the release of heat
16. particle with a positive charge
22. distinguished by its atomic number
24. species formed from chemical reactions
25. central core of an atom