C1 Atomic Structure

Question 1

Who is John Dalton

Answer 1

He thought the atom was a solid sphere that couldn’t be divided ino smaller parts. His model did not include protons,neutrons or electrons

Question 2

The plum pudding model

Answer 2

Scientists found out about sub-atomic charged particles. The first found were electrons

This led to the model of the atom, a cloud of posative charge, with negative electrons embedded in it.

Question 3

Alpha scattering experiment

Answer 3

1. Scientists fired small, positively charged particles (called alpha particles) at a piece of gold foil only a few atoms thick.
2. They expected the alpha particles to travel
   straight through the gold.
3. They were surprised that some of the alpha
   particles bounced back and many were deflected
   (alpha scattering).
4. To explain why the alpha particles were repelled
   the scientists suggested that the positive charge
   and mass of an atom must be concentrated in a
   small space at its centre. They called this space
   the nucleus.

Question 4

Nuclear model

Answer 4

Scientists replaced the plum pudding model with the nuclear model and suggested that the electrons oribut the nucleus, but not at set distances

Question 5

What was Niels Bohr’s model ?

Answer 5

Electron shell (Bohr) model, Niels calculated that electrons must orbit the nucleus at fixed distances. These orbits are called shells or energy levels

Question 6

The proton discovery

Answer 6

Experiments provided evidence that the nucleus contained smaller particles called protons. A proton has an opposite charge to the electron

Question 7

What did James Chadwick discover

Answer 7

James Chadwick carried out experiments that gave evidence for a particle with no charge. Scientists called this the neutron and concluded that the protons and neutrons are in the nucleus, and the electrons orbit the nucleus in shells.

Question 8

Relative mass

Answer 8

The mass of electrons, protons and neutrons comapered to eachother

Question 9

What is an element ?

Answer 9

Substances made of one type of atom

Question 10

What are compounds ?

Answer 10

Made of different types of atoms chemically bonded together

Question 11

What is a mixture ?

Answer 11

Consists of two or more elements or compunds that arn’t chemically combined together. The substances in the mixture can be sperated using physical processes. Thes processes don’t use chemical reactions

Question 12

How do you sperate mixtures ?

Answer 12

Filtration
Crystallisation
Simple distillation
Fractional distillation
Papaer chromatography

Question 13

Filtration

Answer 13

Insoluble solids and a liquid

Question 14

Crystallisation

Answer 14

Soluble solids from a solution

Question 15

Simple distillation

Answer 15

Solvent from a solution

Question 16

Fractional distillation

Answer 16

Two liquids with similar boiling points

Question 17

Papaer chromatography

Answer 17

Identify substances from a mixture in solution

Question 18

How to find the amount of protons

Answer 18

The atomic number

Question 19

How to find the amount of neutrons

Answer 19

Mass number - atomic number

Question 20

How to find the amount of electrons

Answer 20

The same as the number of protons

Question 21

Isotopes

Answer 21

Atoms of the same element with different numbers of neutrons are called isotopes.

Question 22

How to find the relative atomic mass

Answer 22

(Abundence of isotope 1 x mass of isotope 1) + (abundence of isotope 2 x mass of isotope 2) /100

Question 23

Soluble

Answer 23

Dissolves in a solvent

Question 24

Solvent

Answer 24

Liquids for example water