Chemistry Benchmark (Midterm) Review

Copper has two isotopes: Cu-63 (abundance = 69.2%, mass = 62.930 amu) and Cu-65 (abundance = 30.8%, mass = 64.928 amu).  Calculate the average atomic mass of copper.

• 63.55 amu

• 63.5 amu

• 59.55 amu

• 64.9 amu

What is the electron configuration for magnesium?

• 1s^2 2s^2 2p^3

• 1s^2 2s^2 2p^6 3s^2 3p^1

• 1s^2 2s^2 2p^6 3s^2

• 1s^2 2s^2 2p^6 3s^1

How many valence electrons does potassium have?

• 1

• 2

• 8

• 12

Which of the following is not a metal

• iron

• sodium

• oxygen

• magnesium

Which element has the largest atomic radius?

• Si

• S

• Mg

• Na

How many liters are in 50. mL?

• 5000 L

• 0.050 L

• 500 L

• 0.500 L

How many significant digits are in the value 530,405,000?

• 4

• 5

• 6

• 9

Which of the following pairs of elements have similar properties?

• Na and Cl

• Na and K

• Li and He

• O and F

How many electrons does an atom generally need in its outer level to be the most stable?

• 4

• 8

• 10

• 12

Elements that have characteristics of both metals and nonmetals are called:

• Metalloids

• Solids

• Middle Metals

• Nonmetals