1.2 Basic ideas about atoms Flashcards

1
Q

In terms of an atomic nucleus, what is radioactive decay?

A

process that takes place when an unstable atomic nucleus loses energy by radiation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is alpha decay?

A

A type of radioactive decay where an atomic nucleus loses two protons and two neutrons.
It is a helium nucleus
Atomic number is reduced by two and mass number by four, making the element more stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is beta decay?

A

A type of radioactive decay where a beta particle is lost (an electron). And a neutron turns into a proton or vice versa.
Changes atomic number by one mass number, the same

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is positron emission?

A

Positron emission is also known as beta decay.
Beta plus particle has the same mass, the opposite charge to an electron
When it’s released, it increases the nucleus’ proton number by one. No effect on mass number.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is electron capture?

A

process used by unstable, atoms to make them more stable

An electron is drawn into the nucleus and reacts with the proton to form a neutron.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Alpha?

A

helium nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is Gamma?

A

Electromagnetic wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is Beta

A

fast moving electron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is Ionising Radiation?

A

Atoms being hit by radiation energetic enough to cause them to become ions (due to electrons being knocked off)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Alphas ionising power

A

strongly ionising (do to being larger, it is more likely to hit something)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Beta ionising power

A

moderately ionising

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Gamma ionising power

A

weakly ionising (due to being faster, it is less likely to hit something)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what can alpha be blocked by

A

paper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what can beta be blocked by

A

aluminium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what can gamma be blocked by

A

lead

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

why are some atomic nuclei unstable

A
  • there is an imbalance between protons and neutrons
  • they contain too much energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

why do unstable nuclei give out radiation

A
  • they undergo decay to become more stable
  • as they release radiation, their stability increases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the name of the process where an unstable nucleus gives out radiation to become more stable

A

radioactive decay

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

alpha particle response to a magnetic field

A

Weakly attracted to the negative magnetic plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Beta particle response to magnetic field

A

Strongly attracted to the positive plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Positron response to magnetic field

A

Strongly attracted to the negative plate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Gamma radiation response to magnetic field

A

Not affected by the magnetic field (has no change)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

define half life

A

Half-life is the time for the mass of a radioactive substance to decrease to half of its original value

24
Q

why does radioactive decay occur?

A

The radioactivity of substance decrease over time, so it can become more stable

25
Q

Give some uses of radio isotopes

A

-used in medical traces for diagnostic purposes
-used medically to treat cancerous tumours
-Radio dating

26
Q

Why is it bad to come in contact with certain types of radiation?

A

Radiation can damage molecules in a living cell and causes a mutation and DNA. This may make the cell become cancerous.

27
Q

Molar first ionisation energy definition

A

energy required to remove 1 mole of electrons from 1 mole of its gaseous atom to form 1 mole of 1+ ions
X(g) –> X+(g) +e-

28
Q

Molar second ionisation energy definition

A

the energy needed to remove 1mole of electron in 1 mole of gaseous +1 ions to form 1 mole of gaseous ions with a +2 charge

29
Q

how does ionisation energy change attraction

A

The greater the attraction, the greater the ionisation energy

30
Q

What does attraction depend on?

A

size of nuclear charge

The distance of the outer electron for the nucleus

The shielding effect by electrons (in filled inner shells.)

31
Q

size of nuclear charge

A
  • Greater the nuclear charge, greater the attractive force
32
Q

The distance of the outer electron for the nucleus

A
  • The further the distance, the lower the attractive
    force
33
Q

Is ionisation energy, exothermic or endothermic

A

Endothermic

34
Q

The shielding effect by electrons (in filled inner shells.)

A
  • It’s the repulsion between electrons in different shells.
  • Electrons are all negative so repel each other.
  • The more filled inner shells, the lower the ionisation energy.
35
Q

On a graph of first ionisation energy, which group occupy peaks

A

group 0

36
Q

On a graph of first ionisation energy, which group occupy troughs

A

group 1

37
Q

Ionisation energy across a period

A

increases

38
Q

ionisation energy down a group

A

decreases

39
Q

what is an orbital

A

a region within an atom that can hold up to 2 atoms with opposite spin

40
Q

what is a subshell

A

a division of electron shells separated by orbitals
s, p, d and f

41
Q

What rules do electrons follow when filling up orbitals

A
  • electrons always enter lowest energy orbital available
  • electrons prefer to occupy orbitals on their own and will only pair up if there is no empty orbital of the same energy available.
42
Q

How many orbitals are there in S-subshell
(and how many electrons would it hold)

A

1orbital
2 electrons

43
Q

How many orbitals are there in P-subshell
(and how many electrons would it hold)

A

3 orbitals
6 electrons

44
Q

How many orbitals are there in d-subshell
(and how many electrons would it hold)

A

5 orbitals
10 electrons

45
Q

How many orbitals are there in F-subshell
(and how many electrons would it hold)

A

7 orbitals
14 electrons

46
Q

which electron shells, from 1-4 contain which subshells

A

1: s
2: s, p
3: s, p, d
4: s, p, d, f

4s orbital is filled before 3p

47
Q

Explain the origin of emission and absorption spectra in terms of electron transitions

A

when an electron moves down an energy level, a photon is released
when an electron moves up an energy level, a photon is absorbed
the wavelengths of the photons involved are seen using emission and absorption spectra

48
Q

What is the difference between absorption spectra and emission spectra

A

emission spectra =displays lines of emitted photons

absorption spectra = displays spectrum with black lines for missing frequencies (of absorbed photons)

49
Q

How do you calculate ionisation energy

A

planck’s constant x avogadro’s constant x convergence limit

50
Q

how do you calculate frequency

A

(speed of light)/(wavelength)

51
Q

put UV, visible light, infrared radiation in order of decreasing energy

A

UV light
visible light
infrared radiation

52
Q

transition back to N=1

A

lymen series
UV

53
Q

transition back to N=2

A

Balmer series
visible light

54
Q

transition back to N=3

A

Paschen series
infrared

55
Q
A