Year 9- Chemistry- Compounds Molecules and Mixtures

Something counts as a 'molecule' when it's made from 2 or more atoms, and those atoms are held together by chemical bonds. True or false?

True

O2 consists of 2 oxygen atoms, covalently bonded together. Does oxygen count as a molecule?

Yes

Is helium a molecule?

No, helium is a single atom and molecules must contain 2 or more atoms

A compound is a substance made from ___ or more different ______ that are chemically _____ together

-two
-elements
-bonded

Is carbon dioxide (CO2) a molecule, a compound, or both? Why?

Both, it contains 3 atoms that are chemically bonded together. It is also a compound because it contains atoms of 2 elements.

How many oxygen atoms are there in 1 molecule of H2SO4?

4

What is the definition of a mixture?

A mixture is two or more substances that are not chemically combined.

Is the air all around us a compound or a mixture?

Mixture, substances in air are not chemically bonded to each other

Is seawater a compound or a mixture?

Mixture

Define molecule.

A group of two or more atoms bonded by chemical bonds

Define compound

Two or more DIFFERENT elements held together by chemical bonds. Some molecules are also compounds.

Define mixture

Two or more substances that are not chemically combined and that haven't reacted. These can be separated.