Elements, compounds and mixtures

Question 1

what is a pure substance?

Answer 1

a substance made up of a single element or compound

Question 2

how can melting points be used to identify a pure substance?

Answer 2

a pure substance will have a exact melting point

if a substance isnt pure it will melt across a range of temperatures due to the fact that it contains a mixture of elements or compunds

Question 3

What is the difference in melting point and boiling point between a compound and a mixture?

Answer 3

Compound: fixed melting point and boiling point

Mixture: boils over a range of temperatures

Question 3

What is the difference in separation between a compound and a mixture?

Answer 3

Compound: cannot be broken down into simpler substances by physical means

Mixture: easily separated into its substances by physical means

Question 4

What is an element?

Answer 4

An element is a substance that cannot be broken down into simpler substances by ordinary chemical methods.

Question 5

What is a compound?

Answer 5

A compound is a substance containing two or more elements joined together by a chemical reaction. A compound has very different properties from its constituent elements.

Question 6

What is a mixture?

Answer 6

A mixture is whereby the atoms of the elements are not joined together.