Chemistry Atomic Structure and the periodic table

Atom

the smallest part of an element that can exist.

Element

A substance of only one type of atom and cannot be broken down into simpler substances.

How are the elements listed and how many approx are there?

Elements are listed in the periodic table and there are 118 known elements.

Elements can be classified into two groups which are?

Metals and Non metals.

Elements may combine to form new products. What are these called?

Compounds.

What is a compound?

Two or more elements combined chemically in fixed proportions which can be presented by formulae.

Do compounds have the same properties as their constituent elements?

No, they have different properties.

What is a mixture? Does it have the same chemical properties as its constituent materials?

A mixture consists of two or more elements or compounds not chemically combined together, they have the same chemical properties.

What are the methods through which mixtures can be separated?

Filtration, crystallisation, simple distillation, fractional distillation and chromatography.

Do the methods which mixtures can be separated involve chemical reactions?

No they do not contain chemical reactions.