Science 7 Review

What is the difference between pure substances and mixture?

• A mixture is always heterogeneous while a pure substance is always homogeneous.
• A sample of mixture may have two or more phases (heterogeneous) while pure substance always has a uniform phase.
• The boiling point of a pure substance may vary while the boiling point of a mixture is constant.

• Pure substances can be separated physically while mixtures can't be.

Which of the following is a heterogeneous mixture?

• sand in water
• mango shake
• coffee grounds
• salt and water solution

How many significant figure are present in 0.000 560 400 miles?

• 4 SF
• 6SF
• 8SF
• 9SF

Which of the following is an extensive property?

• My hair is longer now than the past few months.
• My hair color is black.
• My hair is shiny.
• My hair smells sweet.

Your group is assigned to measure the length of a block of wood. Your individual measured values are 10 cm, 10.5 cm, 9.90 cm, and 10.3 cm. Your teacher revealed the correct measurement which is 10.0 cm.

In terms of accuracy and precision, your individual measurement is ______.

• accurate and precise
• accurate but not precise
• not accurate but precise
• neither accurate nor precise

In a solution, this component is usually the one with a lesser amount.

• solvent
• solution
• solute
• mixture

Calculate the given operation and express the final answer in proper significant figures:

750 kg / 60 kg

• 12.5

• 13

• 1

• 10

The following are intensive properties of water EXCEPT:

• volume
• boiling point
• melting point
• density

For a few days, Ada is watching the development of a larva into a butterly while taking down notes of the process. What scientific skill is Ada showing?

• drawing conclusions
• making observation
• making hypothesis
• interpreting the data

Which of the following can be a good scientific question?

• Does the color of light affects the growth of chickens?
• Who is the president of Ukraine?
• What makes Saturn the lightest planet in the solar system?
• What makes me awesome?