Elements and Compounds

Front

What is an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means. Examples include hydrogen (H), oxygen (O), and carbon (C).

Front

What is a compound?

Back

A compound is a substance formed when two or more elements are chemically bonded together. Examples include water (H2O) and sodium chloride (NaCl).

Front

What is the chemical formula for water?

Back

H2O

Front

What is the chemical formula for table salt?

Back

NaCl

Front

Which of the following is an example of a compound: H2, O2, NaCl, Cl?

Back

NaCl is a compound.

Front

What is a mixture?

Back

A mixture is a combination of two or more substances that are not chemically bonded. Examples include air and salad.

Front

What is the difference between an element and a compound?

Back

An element is a single type of atom, while a compound consists of two or more different types of atoms chemically bonded together.

Front

What does the symbol 'Cl' represent?

Back

Cl represents the element chlorine.

Front

What does the symbol 'H2' represent?

Back

H2 represents a molecule of hydrogen, which is an element.

Front

What is the smallest unit of a compound?

Back

The smallest unit of a compound is a molecule.