Front

What is a compound?

Back

A compound is a substance formed when two or more elements chemically bond together. For example, NaCl (sodium chloride) is a compound made of sodium and chlorine.

Front

Which one is a compound? Ni, F, Re, NaCl?

Back

NaCl is a compound.

Front

What is the most abundant element in the Earth's crust?

Back

Oxygen is the most abundant element in the Earth's crust.

Front

Which of the following is not a compound? HCl, Cl, NaCl, CO2?

Back

Cl is not a compound; it is an element.

Front

How can you tell how many elements are in a compound?

Back

You can count the capital letters in the chemical formula.

Front

Which elements are commonly found in the Earth's crust?

Back

Common elements in the Earth's crust include oxygen, silicon, aluminum, and iron.

Front

What is the chemical formula for water?

Back

The chemical formula for water is H2O, which means it is made of two hydrogen atoms and one oxygen atom.

Front

What is the difference between an element and a compound?

Back

An element is a pure substance that cannot be broken down into simpler substances, while a compound is made up of two or more elements chemically combined.

Front

What is the chemical symbol for sodium?

Back

The chemical symbol for sodium is Na.

Front

What is the chemical formula for carbon dioxide?

Back

The chemical formula for carbon dioxide is CO2, which consists of one carbon atom and two oxygen atoms.