science

Question 1

elements meaning

Answer 1

A pure substance that cannot be separated into simpler substance by physical or chemical means.

Question 2

compounds

Answer 2

Pure substance composed of two or more different elements joined by chemical bonds.

Made of elements in a specific ratio
that is always the same
Has a chemical formula
Can only be separated by
chemical means, not physically

Question 3

mixtures

Answer 3

A combination of two or more pure substances mingled together that are not chemically combined.

Substances held together by physical forces, not chemical
No chemical change takes place
Each item retains its properties
in the mixture
They can be separated physically

Question 4

quick revision, how may atoms or substances in element, compound and mixtures?

Answer 4

An element contains just one type of atom.
A compound contains two or more different atoms joined together.
A mixture contains two or more different substances that are only physically joined together, not chemically.
A mixture can contain both elements and compounds.

Question 5

name a number of ways mixtures can be seperated

Answer 5

Decanting

Filtration,

Evaporation,

Distillation and

Paper chromatography

Question 6

Decanting means

Answer 6

“pouring off”.

Question 12

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Answer 12

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