GED Science : Matter and Moles

Study concepts, example questions & explanations for GED Science

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Example Questions

Example Question #1 : Matter And Moles

Molecules are constantly moving. In which state of matter do molecules move the fastest?

Possible Answers:

Gases

Solids

Liquids

Molecules move at the same rate in both gases and liquids

Molecules move at the same rate in all three states of matter

Correct answer:

Gases

Explanation:

The movement of particles is important in differentiating the states of matter. Solids have the lowest molecular energy; their molecules barely vibrate and are generally trapped in lattice structures. Molecules in liquids are able to move more freely, resulting in the fluidity of the liquid state. Gas molecules have even more freedom of movement, allowing the gas to expand to fill a space.

Consider that energy (such as heat) must be added to convert a solid to a liquid or a liquid to a gas. That energy goes to make the molecules move faster and increase the temperature of the compound. Gases require the most energy (consider boiling water), and will have the fastest moving molecules.

Example Question #2 : Matter And Moles

Atomic mass values:

Convert the following mass to moles:

Possible Answers:

Correct answer:

Explanation:

To convert grams to moles, use the molecular weight of the molecule. This is found by adding the mass of each atom.

Now we can use the molecular mass to convert the given mass in the question to moles. Make sure to align the values so that the units cancel out.

Example Question #1 : Avogadro's Number

How many molecules are in 3.72mol of fluorine?

Possible Answers:

Correct answer:

Explanation:

Convert from moles to molecules using Avogadro's number:

Use the moles given in the question to solve.

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