Exam 1 review

Which is the chemical change?

• Combustion

• Melting ice

• Mixing sugar and water

• Mixing coke and mentos

Which is NOT the homogenous mixture?

• air

• pure water

• saltwater

• blood

What are the units for measuring density?

• mass / volume

• grams / kelvin

• moles / liters

• mass / meter

•A student has five weeks to complete five assignments and receives the following grades on the assignments: 90, 65, 71, 39, and 58. Is the student precise, accurate, both, or neither?

• Precise

• Accurate

• Neither

• Both

Define precision

• The highest value

• How close results are to each other

• How correct an answer is

• The best result

What is the base SI unit for mass?

• moles

• grams

• liters

• kilograms

What is the unit prefix for 10^-6

• micro

• nano

• pico

• mili

How many significant figures does 0.0000811 have?

• 7

• 4

• 3

• 8

What is the correct scientific notation for 198,000,000

• 19.8 x 10⁸

• 1.98 x 10⁸

• 1.98 x 10⁹

• 198 x 10⁸

Which number has four significant figures?

• 0.0045

• 4500. 4500.

• 4500

• 4520