Atomic Structure

Question 1

What are the characteristics of a proton ?

Answer 1

Located in the nucleus , relative mass of 1 and charge of +1

Question 2

What are the characteristics of a neutron?

Answer 2

Located in the nucleus , relative mass of 1 and charge of 0

Question 3

What are the characteristics of a electron?

Answer 3

Located outside the nucleus , with a mass of 1/1840 and charge of -1

Question 4

What is the arrangement of sub atomic particles ?

Answer 4

The protons and neutrons are held together by a strong nuclear force ,which are stronger than the electrostatic forces of attraction which over comes the repulsions between p+n

Question 5

What does the symbol of A stand for

Answer 5

The mass number of protons plus neutrons in the nucleus

Question 6

What does the Z symbol stand for

Answer 6

The atomic number , the number of protons in the nucleus , the number of electrons are the same as number of protons

Question 7

What are ions

Answer 7

By gaining or losing electrons , they have a sign next to them

Question 8

What are isotopes and properties

Answer 8

Atoms with the same number of protons but different amount of neutrons, different isotopes of the same element have same chemical properties but different physical

Question 9

What is relative atomic mass

Answer 9

The average mass of the atom of an element on a scale where carbon-12 is exactly 12.

Question 10

What is mass spectrometer

Answer 10

Used to analyse compounds, and can find illegal substances

Question 11

How does a mass spectrometer work

Answer 11

• under a high vacuum to prevent ions colliding with air particles
• the sample is ionised by it being dissolved in a polar substance,and pushed through a needle ,and a high voltage is applied causing electron to be lost leaving positive ions
• the + ions are accelerated by the field giving all same Ke,lower mass/charge ration cause greater acceleration
• ions drift through region of no electric field
• ions are detected and times noted of how long they took and ions create a current as they hit

Question 12

How do you interpret a mass spectrum

Answer 12

If a sample is a element each line is a different isotope , the height of the peak gives the relative isotopic abundance

Question 13

How do you calculate relative atomic mass from from a spectrum

Answer 13

• for each peak read the %abundance on the yaxis and the mass on the x and multiply them
• add them up
• divide by 100

Question 14

What is the formula to work out number of electrons

Answer 14

2n^2

Question 15

How many electrons can orbitals have

Answer 15

S-2
P-6
D-10

Question 16

How does arrows in boxes show electronic configuration

Answer 16

Each box represents one orbital , each arrow represents one electron .up and down arrows represent arrows spinning in different directions

Question 17

What are the rules for allocating electrons in boxes

Answer 17

• Lower energy ones are filled first
• fill singly before pairing
• no orbital can hold more than 2

Question 18

How do you write electronic structure

Answer 18

1s2 2s2 2p6 3s1 sodium

Question 19

What is the first ionisation energy

Answer 19

The energy required to remove 1 electron from 1 mole of gaseous atoms to form 1 mole of gaseous ions

Question 20

What is equation for the first ionisation

Answer 20

Element->element +e-

Question 21

What effects ionisation energy

Answer 21

Nuclear charge -more protons stronger attraction
Distance from nucleus- close is more attrative
Shielding -more shells more electrons

Question 22

What is the definition of second ionisation energy and equation

Answer 22

Energy required to remove an electron from each ion in 1 mole of gaseous 1+ions
:element->element^2+ +e-

Question 23

What is the general equation for successive ionisation energies

Answer 23

X(n-1)->X^n+ +e-

Question 24

What is the trend in ionisation energies going down group 2

Answer 24

Ionisation energies decrease down due to the shielding and the electron further away from nucleus

Question 25

What is the ionisation trend across periods

Answer 25

Ionisation energies increase across as harder to remove outer e-

Question 26

Why are ions used in mass spec

Answer 26

Ions are detected at detector

Ions are accelerated

Question 27

How do u calculate relative abundance

Answer 27

      100