Chemistry in Context - Lecture Notes

Flashcards covering key concepts from the lecture on chemistry and the classification of matter.

What is matter?

Anything that occupies space and has mass.

What is a substance?

A specific instance of matter, such as water or metal.

What are the four states of matter?

Solid, liquid, gas, and plasma.

How are solids characterized?

They have a definite shape and are not compressible.

What defines a liquid?

It takes the shape of its container and is not compressible.

What is a gas?

It expands to fill its container and is compressible.

What is the composition of matter?

All matter is comprised of atoms.

What is a molecule?

A collection of two or more atoms held together by chemical bonds.

What is a pure substance?

A substance that has a constant composition, with all specimens having the same makeup and properties.

What differentiates elements from compounds?

Elements cannot be broken down into simpler substances by chemical changes, while compounds can.

What is a mixture?

A combination of two or more types of matter that can be present in varying amounts and can be separated by physical changes.

What are the two classes of mixtures?

Heterogeneous and homogeneous mixtures.

Define a physical property.

A characteristic of matter not associated with a change in chemical composition.

What is a chemical property?

The ability of a substance to change into another type of matter.

What is the significance of extensive properties?

They depend on the amount of matter present.

What are intensive properties?

Properties that do not depend on the amount of matter present.

What does SI stand for?

International System of Units.

What is density?

The ratio of mass to volume of a substance.

What is the formula for calculating density?

Density = mass/volume or d = m/V.

Why is reporting significant figures important?

It reflects the certainty of a measurement.

What would you call the exact number of significant figures in a number?

Those that are not place-holding and reflect measurement precision.

How do you classify a chemical change?

It produces one or more types of matter that differ from the matter present before the change.