Atomic Structure

Question 1

Which 2 subatomic particles are found in the nucleus?

Answer 1

protons and neutrons

Question 2

Name the 2 subatomic particles with opposite charges.

Answer 2

protons and electrons

Question 3

Which came first, the concept of atoms or the concept of electrons?

Answer 3

atoms

Question 4

What is the relative charge on an electron?

Answer 4

-1

Question 5

What is the relative charge on a proton?

Answer 5

+1

Question 6

What is the relative charge on a neutron?

Answer 6

0

Question 7

Atomic number - Z

Answer 7

the number of protons in an atom

Question 8

Mass number - A

Answer 8

total number of protons and neutrons in an atom

Question 9

Isotopes

Answer 9

atoms of an element that have the same number of protons but different numbers of electrons

Question 10

Time of flight (TOF) mass spectrometer

Answer 10

determines the mass of individual atoms within a sample;
from the information the identity of an element or the relative molecular mass of a compound can be found, isotopic abundance can be determined.

Question 11

TOF - types of ionisation

Answer 11

electrospray ionisation and electron impact ionisation

Question 12

TOF - electrospray ionisation

Answer 12

tiny positively charged droplets are produced by gaining H+ ions.

Question 13

TOF - electron impact ionisation

Answer 13

electrons are fired at a sample, knocking electrons off the target atoms to give 1+ ions.

Question 14

TOF - acceleration

Answer 14

+ ions are attracted to a negatively charged plate and accelerate towards it; lighter ions and highly charged ions move faster than others.

Question 15

TOF - ion drift

Answer 15

a beam formed of the + ions passes along the flight tube.

Question 16

TOF - detection

Answer 16

+ ions arrive at the detector and pick up an electron, causing a current; lighter, faster ions arrive first.

Question 17

How sub-shells are filled?

Answer 17

Fill from the bottom.
Each orbital can have only 2, opposite electrons.
Electrons repel, so fill orbitals singly before pairing.

Question 18

Why is the 4s sub-shell filled before 3d?

Answer 18

The 4s sub-shell has lower energy than the 3d.

Question 19

First ionisation energy

Answer 19

the energy required to remove a mole of electrons from a mole of atoms in the gaseous state to give a mole of gaseous ions, each with one positive charge.

Question 20

Successive ionisation energies

Answer 20

First electron - easiest to remove.
Closer to the nucleus more energy is needed to remove electrons.
A big jump in ionisation energy can be seen between shells.

Question 21

Trend in ionisation energies down a group

Answer 21

As the outer electrons get further from the nucleus, less energy is needed to remove them.
This means there is generally a decrease in ionisation energy down a group.

Question 22

Trend in ionisation energy across a period

Answer 22

As nuclear charge increases, electrons become harder to remove.
This means ionisation energy generally increases across a period.

Question 23

How do we calculate the number of neutrons in an atom?

Answer 23

mass number - atomic number

Question 24

What type of ions are produced after ionisation in a time of flight mass spectrometer?

Answer 24

positive

Question 25

List the types of electron orbitals in order from lowest energy to highest.

Answer 25

s, p, d (f)

Question 26

How many d orbitals are there in each electron shell?

Answer 26

5

Question 27

How does ionisation energy change across a period?

Answer 27

generally increases

Question 28

What did Boyle define in 1661?

Answer 28

elements as simplest substances

Question 29

In 1803, what did Dalton define elements?

Answer 29

atoms of the same mass

Question 30

What did Thomson discover?

Answer 30

electrons, development of the plum pudding model

Question 31

Who developed the idea of a nucleus and conducted the gold foil experiment?

Answer 31

Rutherford in 1911

Question 32

Who designed the nuclear model of the atom?

Answer 32

Bohr in 1913

Question 33

In 1926, what did Schrodinger find out about electrons?

Answer 33

can act as waves or particles

Question 34

Who discovered in neutrons?

Answer 34

Chadwick in 1932