1. Answers to Quiz 6 Q

2. 1.ANS:A proton is positively charged, an electron is negatively charged, and a neutron has no charge (or a charge of zero). 2.ANS:The electron cloud is outside the nucleus of the atom. It forms from the electrons, which move rapidly in a spherical space around the nucleus. 3.ANS:Protons and neutrons have the same mass. Both are found in the nucleus.

3. 4.ANS:Atoms of Group 1 elements each have a single valence electron. These atoms easily lose their valence electron, reacting with other elements that can gain electrons, and therefore becoming more chemically stable. The easy loss of the one valence electron makes the Group 1 elements more reactive than metals that must lose two or three electrons in reactions.

4. 5. ANS:A metal crystal consists of positively charged metal ions embedded in a “sea” of loosely held valence electrons that can move around easily. Heat travels through materials as the increased motion of the particles in the hotter parts of the material is passed along to the particles in the cooler parts. In a metal, since particles are easily set into motion, heat is easily transferred, or conducted. The same is true for the conduction of electricity. Electricity can flow when charged particles, like electrons, are free to move. Since the electrons in a metal crystal can move freely among the atoms, electricity is easily conducted.

5. 6.ANS:C 7.ANS:D 8.ANS:C 9.ANS:B 10.ANS:A 11.ANS:B 12.ANS:C

6. 13.ANS:ions 14.ANS:nonpolar 15.ANS:polyatomic 16.ANS:electricity 17.ANS:do not usually react