Atomic Structure

Question 1

What is an atom ?

Answer 1

smallest particle of a chemical element to exist

Question 2

What is an element ?

Answer 2

composed of one type of atom on the periodic table

Question 3

What is a compound ?

Answer 3

2 or more different types of atoms that are chemically bonded

Question 4

What is a mixture ?

Answer 4

2 or more types of elements and/or compounds that are chemically mixed.

Question 5

What does the atomic number represent ?

Answer 5

Number of protons an element has

Question 6

What does the mass number represent?

Answer 6

number of protons and neutrons

Question 7

Where are protons and neutrons located ?

Answer 7

in the atoms nucleus

Question 8

where are electrons located ?

Answer 8

electrons orbit the nucleus in outer shells

Question 9

What is the relative charge of protons, neutrons and electrons ?

Answer 9

Protons = +1
Neutrons = 0
Electrons = -1

Question 10

What is the relative mass of protons, neutrons and electrons ?

Answer 10

Protons = 1
Neutrons = 1
Electrons = 1/1800

Question 11

What are the methods of separating mixtures ?

Answer 11

• Distillation (separating based on boiling point of mixtures)
• Filtration (separating insoluble solids from liquids)
• Fractional distillation (separating crude oil into different hydrocarbons
• Crystallisation
• chromatography

Question 12

Describe the evolution of the particle model ?

Answer 12

• Plum pudding model (sphere of positive charge with negative electrons imbedded
• alpha particle experiment (atoms had a mass centred in the nucleus which had a positive charge
• Neil Bohr = discovered electrons and energy levels
• James Chadwick = discovered the neutron

Question 13

What are group 1 elements ?

Answer 13

Alkali metals

• soft grey metals
• react violently with oxygen
• low density
• low melting point
• low boiling point

Question 14

What are Group 2 elements?

Answer 14

Alkali earth metals

Question 15

What are Group 7 elements ?

Answer 15

Halogens

• highly reactive
• can be used as sterilisers

Question 16

What are Group 0 elements ?

Answer 16

Noble Gasses

• unreactive
• can be used in balloons or neon lights

Question 17

what are transition metals?

Answer 17

Can be used as catalysts

• hard, shiny and conductors
• used as jewellery, wires and saucepans

Question 18

How does Lithium react with oxygen ?

Answer 18

burns with a crimson red flame

Question 19

How does Sodium react with oxygen ?

Answer 19

burns with an orange/yellow flame

Question 20

How does Potassium react with oxygen ?

Answer 20

burns with a lilac flame

Question 21

How does Lithium react with water ?

Answer 21

fizzes and floats

Question 22

How does Sodium react with water ?

Answer 22

melts into a ball, fizzes and bubbles

Question 23

How does potassium react with water ?

Answer 23

burns with a lilac flame and bubbles

Question 24

How does lithium react with halogens ?

Answer 24

forms a white powder

Question 25

How does sodium react with halogens ?

Answer 25

burns with yellow flame and forms white powder

Question 26

How does potassium react with halogens ?

Answer 26

more vigorous reaction and forms a white powder

Question 27

Describe the evolution of the periodic table:

Answer 27

• John Newland arranged elements in octaves where every eighth element had similar properties with increasing masses
• Dimitri Mendeleev ordered the elements based on atomic weight and left gaps for undiscovered elements
• Now, the table is arranged by atomic number and groups with similar properties (same number of electrons in outer shell)