Chemistry Unit 1 Retest

Which one of the following is a chemical change?

• Boiling water

• Evaporating alcohol

• Burning gasoline

• Dissolving sugar in water

Which of the following is a physical change?

• Cooking an egg

• Burning gasoline

• Milk souring

• Dissolving sugar in water

Classify Table salt (NaCl).

• Element

• Compound

• Homogeneous mixture

• Heterogeneous mixture

Two substances physically combined and that appears the same throughout is classified as

• A homogeneous mixture
• A heterogeneous mixture
• An element
•   A compound

Express 67500000 in scientific notation.

• 6.75 X 10⁷

• 6.75 x 10⁵

• 67.5 x 10⁶

• 6.75 x 10^-7

Convert 0.090L to milliliters.

• 9 mL

• .000090 mL

• 90. mL

• 90,000 mL

Which of the following SI unit is best used to express the volume of water?

• Meter

• Gallon

• Pound

• Liter

How many significant digits are in 7.080 x 10²¹?

• 24

• 4

• 3

• 21

using the rule of significant figures, calculate the following: 23.4567 - 3.45=

• 20.0067

• 20.

• 20.007

• 20.01

What is the result of the following expressed in scientific notation and the correct number of significant digits?

(3.04 x 10⁵)(5.0 x 10^-8)

• 0.0152

• 1.5 X 10^-2

• 1.52 x 10^-2

• 0.015