Semester 2 Quiz 1: Study Guide

1. What are physical properties?
- Look for color, density, and odor.

2. What is a physical change?
- Melting, boiling, and bending; the material remains the same, even though its form has changed.

3. What is a chemical change?
- When a substance changes into one or more new substance.

4. What are chemical properties?
- Determine the usefulness of a substance; relates to any kind of chemical change.

5. How do you detect a chemical change?
- By observing one or more indications of a change, such as the formation of a gas or solid, a permanent color change, or a temperature change, which indicates that thermal energy has been adsorbed or given off.

6. What is combustion?
- Burning

7. What is luster?
- Shiny and reflect light

8. What is ductile?
- Can be drawn into wires

9. What happened with copper?
- Too expensive and in short supply.

10. What is the story of zinc?
- Replaced copper because it had nearly the same density and just as hard, but it's more chemically reactive than copper.

11. Common Elements and Their Symbols
Al: Aluminum
Sb: Antimony
Ar: Argon
Ba: Barium
Be: Beryllium
Bi: Bismuth
B: Boron
Br: Bromine
Cd: Cadmium
Ca: Calcium
C: Carbon
Cs: Cesium
Cl: Chlorine
Cr: Chromium
Co: Cobalt
Cu: Copper
F: Fluorine
Au: Gold
He: Helium
H: Hydrogen
I: Iodine
Fe: Iron
K: Krypton
Pb: Lead
Li: Lithium
Mg: Magnesium
Mn: Manganese
Hg: Mercury
Ne: Neon
Ni: Nickel
N: Nitrogen
O: Oxygen
P: Phosphorus
Pt: Platinum
Potassium: K
Rn: Radon
Si: Silicon
Ag: Silver
Na: Sodium
S: Sulfur
Sn: Tin
W: Tungsten
U: Uranium
Zn: Zinc

12. What are metals?
- Have a luster, are malleable (can be hammered into sheets), and conduct electricity, react with acid and copper(II) chloride solution.

13. What are nonmetals?
- Dull in appearance, brittle, and do not conduct electricity?

14. What are metalloids?
- Same properties as metals and nonmetals.

15. What has the least mass: electrons, protons, or neutrons?
- Electrons

16. Which has a neutral charge?
- Neutrons

17. Which has a positive charge?
- Protons

18. If an atom has 10 protons, how many electrons must it have?
- 10

19. NaCl and H2O are both molecular compounds. Is there a difference in how the atoms of each are held together? Briefly explain.
- NaCl is an ionic compound and H2O is a covalent compound. Ionic compounds aren't as strong so NaCl is less strong than H2O.

20. Write a symbol and show the electrical charge (if any) on the following atoms or ions:
      A. Magnesium (Mg) with 10 electrons: Mg2+
      B. Fluorine (F) with 10 electrons: F-

21. True or false combustion causes a chemical change?
- True.

22. When the price of copper was more than one cent, they started making pennies with a zinc core and a copper exterior. Why did they not make the whole penny out of copper? Why did the not make the whole penny out of zinc?
- Too costly
- Easily destroys and doesn't keep form.