Compounds and Mixtures

Compounds

You will need to know:

The differences between a compound and an element.

The difference between a pure substance and a mixture

Compounds form when two or more elements react together and chemically combine.

A pure substance is when there is only__ one kind of particle__ in a substance

A __mixture __is when two or more types of particles occupy the same space, but are not chemically joined together.

Compounds and Mixtures, figure 1

How Compounds Form

You will need to know:

The basics of how compounds form.

Atoms chemically combine when they either share electrons __or __give electrons to each other.

When metals and non-metals react, the metal atom gives electrons to the non-metal. This means that the metal atom becomes positively charged and the non-metal atom becomes negatively charged. Since the two have opposite charges, they become very attracted to each other and form a compound!

Compounds and Mixtures, figure 1

When two non-metals react, they share electrons with each other. Since both atoms need the electrons that are being shared, this forms a strong bond between the two, forming a different kind of compound!

You will learn more about this in the Bonding and Properties of Matter section.

Properties of Compounds

You will need to know:

That a compound have very different qualities to that of it’s individual element components.

The properties of compounds are usually very different to the original elements that make up the compound.

For example, when Iron and Sulfur are heated together, they create Iron Sulfide. Iron Sulfide doesn’t behave (or look) anything like Iron or Sulfur!

Compounds and Mixtures, figure 1

Examples of Compounds and Mixtures

This section is just to bring it all together!

If you are uncertain on any of the following:

  1. Pure substance
  2. Mixture
  3. Compound
  4. Element

then these examples might set things straight…

Compounds and Mixtures, figure 1

  1. Pure substance(since all particles are the same)of ____compounds(since each particle is made up of different types of atoms)
  2. Pure substance__ (since all particles are the same)__ of ____compounds(since each particle is made up of different types of atoms)
  3. Mixture(since all particles are NOT the same)__ of__Elements(since each particle is made up of the same type of atom)
  4. Mixture(since all particles are NOT the same)__ of __Elements(since each particle is made up of the same type of atom)__ and __compounds__ (since each particle is made up of different types of atoms)__