Chemistry Test 1 Review

Front

What is a molecule?

Back

A molecule is a group of two or more atoms bonded together. Examples include water (H2O) and carbon dioxide (CO2).

Front

Which of the following is NOT a molecule? A) H2O B) CO2 C) O2 D) Na

Back

D) Na (Sodium is an element, not a molecule).

Front

How many atoms are in a water molecule?

Back

A water molecule (H2O) contains 3 atoms: 2 hydrogen atoms and 1 oxygen atom.

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances and is made of only one type of atom.

Front

What is a compound?

Back

A compound is a substance formed when two or more different elements are chemically bonded together, such as water (H2O) or carbon dioxide (CO2).

Front

What is a mixture?

Back

A mixture is a combination of two or more substances that are not chemically bonded, such as saltwater or air.

Front

What is a heterogeneous mixture?

Back

A heterogeneous mixture is a mixture that is not uniform throughout, meaning its components can be easily distinguished, like a salad.

Front

What is a homogeneous mixture?

Back

A homogeneous mixture is a mixture that is uniform in composition, meaning its components are evenly distributed, like sugar dissolved in water.

Front

What is density?

Back

Density is the mass of a substance divided by its volume, often expressed in grams per cubic centimeter (g/cm³).

Front

If a substance has a density less than 1 g/cm³, will it float or sink in water?

Back

It will float, as it is less dense than water.