Topic 2: Atomic structure

Question 1

What is mass number

Answer 1

Protons + neutrons

Question 2

What is atomic number equal to

Answer 2

protons and electrons

Question 3

Chemical and physical properties of isotopes

Answer 3

Same chemical properties
Diff physical properties - the heavier one
- higher mass
- higher density
- higher rate of diffusion

Question 4

Steps in a mass sepctrometer

Answer 4

1. vaporization - must be gas
2. ionization - shoots our negative electrons to make positive atoms bc it knocks off the electrons
3. acceleration - electric field accelerates the positive atoms
4. deflection - curves down tube through magnetic field - deflection changes depending on the mass of the ion and its charge
5. detection - detector sends electrical signal to recorder
   - detects ions with m/z (mass to charge) ratio, high mass/low charge ratio means less deflection
   - low mass/high charge means more deflection

Question 5

What are radioactive isotopes

Answer 5

Nuclei of the atoms break down spontaneously and emit radiation when doing so, gamma, beta and alpha radiation.

Question 6

Uses of radioactive isotopes

Answer 6

C60 used for chemotherapy radiation (radiotherapy)
I 131 and I 125 used as tracers in medicine for treating and diagnosing illness
C14 used for carbon dating (determining of the age or date of organic matter)

Question 7

Velocity formula for electromagnetic spectrum

Answer 7

Velocity (m s^-1) = Wavelength (M) * frequency (s ^-1)

Question 8

Compare ratio of wavelength and frequency on electromagnetic spectrum

Answer 8

smaller wavelength = higher frequency
longer wavelength = lower frequency

they are inversely proportional

Question 9

Does a low or high frequency have more energy

Answer 9

higher frequency more energy

Question 10

Electromagnetic spectrum from low frequency to high frequency

Answer 10

Radio - microwaves - infrared - visible - uv - x-rays - gamma

Question 11

What is a line spectrum

Answer 11

Selected frequency of emissions that is unique to each element - reflect the atomic rings of the element

Question 12

Describe the line spectrum of hydrogen

Answer 12

Converge at higher frequencies because the energy levels of hydrogen converge at higher frequencies

(lines get closer and closer together)

Question 13

Explain the emission spectra

Answer 13

When energy is supplied to an atoms electrons in its ground state it gets excited and jumps to a higher energy level, eventually it drops to a lower energy level and in doing so emits a photon of energy, dropping to n = 3 releases infrared, n = 2 releases visible n = 1 releases ultraviolet. Bigger drop = more energy.

this energy released corresponds to a particular wavelength and shows up as a line emission spectrum

Question 14

What are the four orbitals

Answer 14

spdf

Question 15

exceptions to electron configuration

Answer 15

when a d orbital is at 4 or 9 and about to complete, they’ll steal from the S2 orbital and itll become S1 and D5 or D9

• its more stable and the electrons dont want to share an orbital - they wanna get away from each other

Question 16

What are the quantum numbers and what do they mean

Answer 16

n = 1 2 3 4 energy level
L = shape of orbital (0 = s, 1 = p, 2 = d, 3 = f)
M sub l = which specific orbital (-L to L)
M sub s = spin (+1/2 and -1/2)