compounds and mixtures

What is a compound?

Substances that contain two or more different elements it’s formed when atoms of two or more elements are chemically bonded together

These elements involved are always found in the same proportions

What is a molecule

A group of two or more atoms held together by chemical bonds (can contain different elements eg O2 or H2O)

How do compounds form?

Atoms combine by transferring or sharing electrons to form bonds—ionic bonds (transfer) or covalent bonds (sharing).

What is an ionic bond?

A bond formed when metal atoms lose electrons to form positive ions and non-metal atoms gain electrons to form negative ions.

What is a covalent bond?

A bond formed when non-metal atoms share electrons.

Give an example of a compound and its formula.

Carbon dioxide (CO₂) — 1 carbon atom and 2 oxygen atoms.

How can you separate elements in a compound?

Only by chemical reactions, not physical methods.

What are the properties of compounds compared to their elements?

Compounds can be small or great big structure called lattices

Once a compound has been formed the element cannot be seperatef by physical processes the only way to separate is by more chemical reactions

What is a mixture?

A combination of separate substances (elements or compounds) not joined by chemical bonds and easily separated by physical methods.

How do the properties of mixtures compare to their components?

They show the properties of all the components without change.

Name three physical methods to separate mixtures.

Filtration, distillation, and chromatography.

What do mixtures consist of? Why can it be easily seperated

Two or more substances that are not chemically bonded together

Mixtures contain different substances that haven’t reacted so they are easily seperated using physical methods like filtration distillation etc