Chemistry Unit 1 Review

Convert 75 kJ = ____cal

4.184 J = 1 cal

1000 J = 1 kJ

• 17.925
• 17,925
• 75,000
• 0.75

How would you write 564,000,000 in scientific notation?

• 5.64 x 10^-7
• 5.64 x 10⁶
• 5.64 x 10⁸
• 56.4 x 10⁷

How many significant figures does the following number have: 0.002040

• 6
• 4
• 3
• 2

How many significant figures does the following number have: 100.3

• 4
• 3
• 5
• 2

calculate the following to the correct number of sig figs.
0.00401  x  2.00  x  501

• 4.02
• 4
• 4.0
• 4.0180

calculate the following to the correct number of sig figs.
32.451 - 21.5

• 11.0
• 10.951
• 11
• 10.95

You know 1000 mg = 1 g.  Convert 2.5 grams into milligrams.

• 25 mg
• 25,000 mg
• 250 mg
• 2500 mg

Which of the following is NOT a physical change?

• grinding

• cutting

• boiling

• burning

The number of significant figures in the measurement 2010 is

• 1

• 2

• 3

• 4

Which statement best describes an element?

• any combination of two or more atoms of different types

• a pure substance made up of only one kind of atom

• a substance containing only carbon atoms

• any kind of crystal