1.2 Basic Ideas of Atoms

Question 1

What effects ionisation energy?

Answer 1

Distance of outer shell from nucleus – the attraction decreases the further away the outer electron is from the nucleus
Nuclear charge – the greater the nuclear charge, the greater the attraction for the outer electron.
Electron shielding – filled inner shells or subshells of electrons act as shields. The outer electron is shielded from the nuclear charge by these shells or sub-shells

Question 2

What is molar ionisation energy?

Answer 2

the energy required to completely remove one mole of electrons from one mole of its gaseous atoms to form 1 mole of gaseous 1+ ions

Question 3

What is standard molar ionisation energy?

Answer 3

At 1 atm pressure and 25 degrees, the energy required to completely remove one mole of electrons from one mole of its gaseous atoms to form 1 mole of gaseous 1+ ions

Question 4

how many electrons in the s orbital?

Answer 4

2

Question 5

how many electrons in the p orbital?

Answer 5

6

Question 6

how many electrons in the d orbital?

Answer 6

10

Question 7

What is the shape of a s orbital?

Answer 7

spherical

Question 8

What is the shape of a p orbital?

Answer 8

dumbell

Question 9

Why has lithium got a higher first ionisation energy compared to sodium?

Answer 9

Li has a higher first ionisation energy because the outermost electron is closer to the nucleus experiencing less shielding, outweighing the increased nuclear charge of sodium

Question 10

Why does Kr have a lower first ionisation energy than Ne?

Answer 10

Kr has a lower first ionisation energy than Ne because its outer electron is further away from the nucleus, experiencing greater shielding that outweighs the increased nuclear charge

Question 11

What is the general trend of ionisation energy in groups?

Answer 11

as you go down the group, the first ionisation energy decreases
because the outer electron becomes further away from the nucleus, experiencing greater shielding, outweighing the increased nuclear charge

Question 12

What is the general trend of ionisation energy in periods?

Answer 12

as you go from left to right across a period, the ionisation energy increases
because the outermost electron remains the same distance from the nucleus and experiences the same shielding, while the nuclear charge increases

Question 13

Why is the second ionisation energy of sodium greater than that of magnesium?

Answer 13

Na- 1s2, 2s2, 2p6, 3s1
Mg- 1s2, 2s2, 2p6, 3s2
the second electron being removed in sodium is closer to the nucleus than that of magnesium, therefore experiences less shielding

Question 14

What is the relative mass of a proton?

Answer 14

1

Question 15

What is the relative mass of a electron?

Answer 15

almost 0
1/1840

Question 16

What is the relative mass of a neutron?

Answer 16

1

Question 17

What is the relative charge of a proton?

Answer 17

+1

Question 18

What is the relative charge of a electron?

Answer 18

-1

Question 19

What is the relative charge of a neutron?

Answer 19

0

Question 20

What is an isotope?

Answer 20

the same element, with the same number of protons but different number of neutrons

Question 21

What are ions?

Answer 21

charged particles where the number of electrons is not equal to the number of protons.

Question 22

What are the types of radioactive emission?

Answer 22

alpha
beta
gamma

Question 23

What is alpha?

Answer 23

2 protons and 2 neutrons
helium nucleus

Question 24

What is beta?

Answer 24

high energy electron

Question 25

What is gamma?

Answer 25

High energy electromagnetic wave

Question 26

What is the mass of alpha?

Answer 26

4 atomic mass unit

Question 27

What is the mass of beta?

Answer 27

almost 0 negligible

Question 28

What is the mass of gamma?

Answer 28

almost 0

Question 29

What is the effect of the electromagnetic field on alpha?

Answer 29

attracted to the negative plate

Question 30

What is the effect of the electromagnetic field on beta?

Answer 30

attracted to the positive plate

Question 31

What is the effect of the electromagnetic field on gamma?

Answer 31

no effect

Question 32

What is the penetrating power of alpha?

Answer 32

stopped by a sheet of paper

Question 33

What is the penetrating power of beta?

Answer 33

stopped by 0.5cm of aluminium

Question 34

What is the penetrating power of gamma?

Answer 34

stopped by more than 2cm of lead

Question 35

Does gamma change the mass/atomic number of an atom?

Answer 35

no because it is a form of energy and is not an atomic particle

Question 36

Does alpha emission change the mass/atomic number of an atom?

Answer 36

yes when emitted it cause the mass number to decrease by 4 and the atomic number to decrease by 2 2 places to the left in the periodic table

Question 37

Does beta change the mass/atomic number of an atom?

Answer 37

yes mass number is unchanged and the atomic number increases by 1 1 place to the right in the periodic table

Question 38

What is electron capture?

Answer 38

when one of the electrons is captured by a proton, turning it into a neutron Atomic number goes down by one

Question 39

What is positron emission?

Answer 39

a proton is converted to a neutron resulting in the emission of a positron Atomic number goes down by one 1 to the left in the periodic table

Question 40

What is half-life?

Answer 40

the time taken for half of the radioactive nuclei in a sample to decay

Question 41

What can ionising radiation do to the body?

Answer 41

DNA can become damaged, which can cause mutations and cancerous cells

Question 42

Which wave has the highest frequency?

Answer 42

gamma rays

Question 43

What equation links energy and frequency?

Answer 43

E=hf

Question 44

What is h?

Answer 44

planck's constant and is unchanged

Question 45

What equation links speed of light and frequency?

Answer 45

c=f x lamda(wavelength)

Question 46

What is c?

Answer 46

speed of light which is unchanged

Question 47

What is the absorption spectra?

Answer 47

this displays an entire spectrum with black lines for the 'missing' frequencies of photons that have been absorbed when an electron moves up an energy level

Question 48

What is the emission spectra?

Answer 48

this displays lines at the specific frequencies of emitted photons from when an electron moves down an energy level

Question 49

What is the hydrogen spectrum?

Answer 49

it is an emission spectrum the lines represent energy released as the promoted electron falls back down to lower energy levels or shells. Each line is equal to the difference in energy, between two particular energy levels, which means it is a quantum

Question 50

What is Lyman's series?

Answer 50

The lines in the Lyman series are in the area with highest frequency/energy (ultraviolet) This is because they are due to electrons falling down to the n=1 shell (closest to the nucleus)

Question 51

What is Balmer's series?

Answer 51

is in the visible part of the spectrum, which has lower energy. Lines here are due to electrons falling down to the n=2 shell

Question 52

Ionisation of the hydrogen atom

Answer 52

can be measured using the convergent frequency of the Lyman series the spectral lines get closer and closer together as the frequency of the radiation increases until eventually they converge together This is known as the convergence limit. When the electron reaches this, its energy is no longer quantised and the nucleus has lost all influence over the electron, so the atom has become ionised