3.1.1 Atomic Structure

Question 1

What is the mass of a proton?

Answer 1

1

Question 2

What is the mass of a neutron?

Answer 2

1.001

Question 3

What is the mass of an electron?

Answer 3

0.000005

Question 4

What is J.J Thomson’s discovery?

Answer 4

Electrons were smaller than at atom.
Came up with the plum pudding model- electrons were embedded within a positively charged ball of atoms.

Question 5

What did Rutherford discover?

Answer 5

Atoms are mostly empty space with a core that is positively charged.
He done this by firing alpha particle at a gold foil and observing that some of the alpha particles bounced back.

Question 6

What did James Chadwick discover?

Answer 6

The nucleus is made up of both protons and neutrons.

Question 7

What is an isotope?

Answer 7

Different versions of the same elements with a different number of nuetrons

Question 8

Define the relative atomic mass

Answer 8

The relative atomic mass (Ar) is the average mass of atoms of an element relative to the mass of an atom of carbon-12

Question 9

How does nuclear charge vary across a period?

Answer 9

It increases by 1 as proton number increases

Question 10

What happens to nuclear charge as we go down a group?

Answer 10

It increase as the number of protons increases

Question 11

What is nuclear charge?

Answer 11

The collective charge of all protons in a nucleus.

Question 12

As the electrons distance from the nucleus increases____

Answer 12

The forces it experiences decreases

Question 13

Across a period, the distance between the nucleus and the outer electrons_____

Answer 13

Decreases, this is because the nuclear charge increases so it pulls the shells towards the nucleus

Question 14

As we move down a group, the distance between the nucleus and the outer electrons______

Answer 14

Increase as the outer electrons are in a different shell.

Question 15

What is shielding?

Answer 15

Each electrons shields some of the nuclear charge from the other electrons. An electron closer to the nucleus would shield the charge of a proton

Question 16

As we move across a period, shielding____

Answer 16

Is the same

Question 17

Down a group, the amount of shielding in the outer electrons…

Answer 17

Increases

Question 18

What is ionisation energy

Answer 18

The energy required to remove one mole electrons from one mole of gaseous atom of that element.

Question 19

As you go down a group, first ionisation energy…

Answer 19

Decreases. This is because the outer electrons become more shielded and further away from the nucleus so less energy is required to remove the electron

Question 20

Across a period, first ionisation energy…

Answer 20

Increases.

This is because nuclear charge increases whilst shielding stays the same, therefore the outer electrons experience stronger attraction to the nucleus.

Question 21

Why is there a dip in ionisation energy between magnesium and aluminium?

Answer 21

• There outer electrons are in different sublevels.
  Magnesium: 3s
  Aluminium: 3p
  Therefore, as aluminium has a 3p orbital which is further from the nucleus and shielded from inner electrons it requires less energy.

Question 22

Explain why there is a dip in ionisation energy between phosphorus and sulfur.

Answer 22

Both phosphorus and sulphur have electrons in the 3p orbital. However sulfur has one paired electron which experiences extra repulsion. Therefore requiring less energy then phosphorus.

Question 23

what is stage 1 of mass spectrometry?

Answer 23

Ionisation:
the sample is first vapourised and an electron gun fires electrons knocking off one electron, making them 1+ ions.

Question 24

what is stage 2 of mass spectrometry?

Answer 24

acceleration:
the positive ions are accelerated by an electric plate with the same kinetic energy. this means that heavier particles will be slower and lighter ones will move faster.

Question 25

what is stage three of mass spectrometry?

Answer 25

Ion drift:
the ions are in a vacuum to stop them from slowing down, they carry on drifting toward the next stage.

Question 26

What did dalton discover?

Answer 26

Elements react together in different proportion but always in whole number ratios.- found the existence of atoms

Question 27

what is the last stage of mass spectrometry?

Answer 27

Detector:
The ions gain an electron from the plate. This movement of electrons creates a current which is detected by a computer which creating a mass spectra.

Question 29

What experiment did Rutherford do?

Answer 29

He done this by firing alpha particle at a gold foil and observing that some of the alpha particles bounced back.

Question 30

What is nuclear force?

Answer 30

Protons and neutrons are held together by this

Question 31

What similar properties do isotopes have?

Answer 31

Same chemical properties

Question 32

What is the mass number?

Answer 32

The number of protons and neutrons.

Question 33

What is an ion?

Answer 33

At atom with a positive or negative overall charge

Question 34

What is the atomic number?

Answer 34

The number of protons

Question 35

Where does mass and atomic number go?

Answer 35

Mass number
Atomic number

Question 36

What is the period table ordered by?

Answer 36

Proton number