Name:
Homework 2
Purple Due Date: April 29 & Green Due Date: April 30
Bonding Review
1) Determine the ionic bond formulas created when the following pairs of elements bond:
a. Magnesium and Germanium
Mg2Ge
b. Sodium and Sulfur
Na2S
c. Potassium and Iodine
KI
d. Strontium and Boron
Sr3B2
2) Which of the following answer choices shows the correct compound formed when Lithium and Silicon bond?
a. LiSi
b. LiSi4
c. Li4Si
d. Li4Si7
3) Which of the following answer choices shows the correct compound formed when Beryllium and Oxygen
bond?
a. Be6O2
b. BeO
c. Be2O2
d. Be2O6
4) How do bonds form?
Bonds form when valence electrons from atoms combine between metals and nonmetals or nonmetals and metals.
5) What happens to bonds during a chemical reaction?
Bonds break and reform during chemical reactions in order to produce something new.
6) What happened to bonds during a physical reaction?
Bonds DO NOT break and reform. They remain in tact because nothing new is created in a physical reaction.
Physical and Chemical Properties Review
1) Identify each of the following as a physical or chemical property. Put a P next to the physical properties, and put
a C next to the chemical properties.
a. Oxygen is odorless and colorless. P
b. Copper turns green when exposed to the environment. C
c. The piece of iron metal is magnetic. C
d. The density of water is 1.0 gram per milliliter P
e. Diamonds are a very hard substance. P
Lab Skills Practice
1) Use the following word bank to match the correct tool of measurement to its proper label. Word bank:
graduated cylinder, cup, Erlenmeyer flask, pipette, beaker, volume ruler
pipette
Erlenmeyer Flask
Graduated Cylinder
Beaker
2) Which of the following pieces of equipment would you use to measure the mass of an object?
a. Beaker
b. Graduated cylinder
c. Massing scale
d. Electronic balance
e. Density
Physical vs. Chemical Change
1) Identify each of the following as a physical or chemical change. Put a P next to the physical changes, and put a C
next to the chemical changes.
a. Water evaporates into steam P
b. A bicycle chain rusts C
c. Eggs turn into an omelet C
d. A popsicle melts P
e. Food is digested in the stomach C
Types of Chemical Reactions
1) Determine what type of chemical reaction each of the following examples is. (Hint: there are 5 types of chemical
reactions – synthesis, decomposition, single displacement, double displacement, and combustion.)
a. Mg + O2  2 MgO
synthesis
b. CaCl2  Ca + Cl2
decomposition
c. NaClO3  2 NaCl + 3 O2
d. Fe + 2 HCl  FeCl2 +
decomposition
H2 single displacement
e. CH4 + 2 O2  CO2 + 2 H2O combustion
2) Which of the following diagrams represents a single exchange reaction?
a. AB + CD  CB + Ad
b. AB + C  ABC
c. AB + C  A + BC
d. ABC  A + BC
Counting Atoms
Use the following chemical reaction equation to answer questions 1 – 3.
2H2 + O2  2H2O
1) a. How many reactants are there? 2
b. How many products are there? 1
2) Count the number of atoms of each element found on the reactant side of the above chemical reaction
equation.
a. H = 4
b. O = 2
3) Count the number of atoms of each element found on the product side of the above chemical reaction equation.
a. H = 4
b. O = 2
4) How many of each atom are in 4C2H8?
a. C = 8
b. H = 32
5) How many of each atom are in H3PO4?
a. H = 3
b. P = 1
c. O = 4