Atoms

Question 1

Where’s are the electrons?

Answer 1

On orbitals

Question 2

Relative mass of proton?

Answer 2

1

Question 3

Relative number of neutron

Answer 3

1

Question 4

Relative number of electron

Answer 4

1/1800

Question 5

Charge of proton

Answer 5

+1

Question 6

Charge of neutron

Answer 6

0

Question 7

Charge of electron

Answer 7

-1

Question 8

On the periodic table which number is the total number of protons and neutrons in the shell?

Answer 8

Mass number the bigger one

Question 9

What’s the smaller number on the periodic table?

Answer 9

Atomic mass number of protons in the nucleus.

Question 10

Define isotope

Answer 10

Atoms with same number of protons but different number of neutrons

Question 11

Why do isotopes have similar chemical structure?

Answer 11

Same electronic structure

Question 12

Why might isotopes have slight differing physical properties?

Answer 12

Different masses

Question 13

What can mass spectrometer be used for?

Answer 13

To determine all isotopes present in a sample of an element and therefore identify elements

Question 14

Why does mass spectrometer need to happen underneath a vacuum?

Answer 14

Air particles would ionise and register on the detector

Question 15

What are the four stages of mass spectrometer?

Answer 15

1) ionisation
2) acceleration
3) drift area
4) detection

Question 16

What happens in ionisation?

Answer 16

Sample dissolved in polar solvent
High voltage applied to sample
Particles lose an electron (or more)
Form positive charges with different charges

Question 17

What happens in acceleration?

Answer 17

Positive ions accelerated by electric field

To constant kinetic energy

Question 18

What’s in the nucleus of an atom?

Answer 18

Proton and neutrons

Question 19

What’s in drift area?

Answer 19

Positive ions with smaller m/z values will have same energy as those with larger m/z values and will move faster. Heavier particles take longer through the drift zone. Ions are distinguished by different flight times

Question 20

What’s in detection?

Answer 20

Ions reach detector and generate a small current which is fed into computer for analysis. Current produced by electrons transferring from detector to positive ions. Size of current is proportional to the abundance of the species.

Question 21

How to calculate RAM?

Answer 21

RAM= all(isotope mass* relative abundance)/ total relative abundance.

Question 22

First ionisation define ?

Answer 22

The first ionisation energy is the enthalpy change when one mole of gaseous atoms forms mole of gaseous ion with a single positive charge
H(g)->H+(g) +e-

Question 23

Ionisation two?

Answer 23

The second ionisation energy is the enthalpy change when one mole of gaseous ion forms one mole of gaseous ions with a double positive charge
H+(g) -> H2+(g) +e-

Question 24

What are the shells

Answer 24

S
P
D
F

Question 25

What are the factors that affect ionisation energy?

Answer 25

1) attraction of the nucleus
2) distance from the nucleus
3) shielding of the attraction of the nucleus

Question 26

Why are successive energies always larger?

Answer 26

When the first electron is removed a positive charge is formed. Ions increases attraction on remaining electrons so energy required to remove the next election is larger.