Elements and Compounds

What is an element?

• A substance that cannot be broken down into simpler substances by chemical means.

• A substance that can be broken down into simpler substances by physical means.

• A substance that is composed of only one type of atom.

• A substance that can be broken down into simpler substances by chemical means.

Give an example of an element.

• Oxygen

• Nitrogen

• Carbon

• Hydrogen

What is a compound?

How are compounds different from elements?

• Compounds are made up of two or more elements physically combined, while elements are pure substances made up of only one type of atom.

• Compounds are made up of only one type of atom, while elements are made up of two or more different elements chemically combined.

• Compounds are pure substances made up of only one type of atom, while elements are made up of two or more different elements chemically combined.

• Compounds are made up of two or more different elements chemically combined, while elements are pure substances made up of only one type of atom.

What is the chemical symbol for oxygen?

• O

• C

• N

• H

What is the chemical symbol for carbon?

• Co

• C

• Ca

• Cu

What is the chemical formula for water?

• HO

• O2

• H2O

• H2O2

What is the chemical formula for carbon dioxide?

What is the difference between a molecule and a compound?

• A molecule is a group of atoms bonded together, while a compound is a molecule that contains at least two different elements.

• A molecule is a compound that is not stable, while a compound is a stable molecule.

• A molecule is a compound that contains only one element, while a compound contains multiple elements.

• A molecule is a group of atoms that are not bonded together, while a compound is a molecule that contains at least two different elements.

Give an example of a compound.

• air

• rock

• fire

• water