Elements

Question 1

What is an element

Answer 1

An element is a pure substance
All the atoms in an element are of the same kind
For example oxygen is made up just oxygen molecules
Copper is made up of just copper atoms

Question 2

What is the periodic table

Answer 2

All known elements are listed in the periodic table
The elements are listed in order of how big their atoms are
Elements that are lime each other are grouped together
All metals on the left hand side
All non metals on the right hand side
The more reactive the metal, the nearer it is to the left hand side
The last column on the right has elements that hardly react at all
Elements are represented by symbols - about 100 in total

Question 3

The main elements (part 1) to know are

Answer 3

Hydrogen - H
Helium - He
Lithium - Li
Neon- Ne
Boron- B
Carbon - C
Nitrogen - N
Oxygen - O
Magnesium - Mg
Aluminium- Al
Phosphorous-P
Sulphur -S

Question 4

The main elements part 2

Answer 4

Chlorine- Cl
Argon - Ar
Potassium - K
Calcium - Ca
Copper - Cu
Zinc - Zn
Lead - Pb
Gold - Au
Silver - Ag
Sodium - Na
Nickel - Ni
Iron - Fe

Question 5

What happens when elements combine

Answer 5

Elements combine to create compounds.

Everything is made up of different combinations of elements

Question 6

What is a molecule

Answer 6

A molecule is made up of more than one atom
Molecules can be either elements or compounds
Some molecules have a single atom
Some are made up of molecules of 2 atoms each eg oxygen and hydrogen

Question 7

How is a compound formed?

Answer 7

When 2 or more elements react together in a chemical reaction a compound is formed
A compound is very different from the elements that make it and it is very difficult or impossible to return them to elements again

Question 8

What is salt

Answer 8

Salt is sodium chloride - NaCl
Sodium is very reactive soft grey metal
It reacts violently with water and chlorine
Chlorine is a green poisonous gas used as disinfectant in swimming pools

Question 9

What is the difference between an element a compound and a mixture

Answer 9

Element atoms are all the same even if they exist as molecules
Compound molecules will all be the same but made up of different elements joined together
Mixtures can be any variety but atoms will certainly not be the same