Expert Chemistry Tutoring

MS1 (1 mark)

Absorption of light by an atom, causing an electron to move to a higher energy level

MS2 (2 marks)

- Electrons gain energy by absorbing photons (1)

- Photons are of a specific wavelength/frequency (1)

MS3 (2 marks)

- Energy is lost as a photon is emitted (1)

- Wavelength/frequency of the photon is specific to the energy difference (1)

MS4 (3 marks)

- Correct substitution: E = hc/λ (1)

- Correct units: λ converted to m (1)

- Calculation: E = (6.63 x 10^-34 J s) x (3.00 x 10^8 m s^-1) / (589 x 10^-9 m) = 3.37 x 10^-19 J (1)

MS5 (3 marks)

- Correct layout and labeling of energy levels (1)

- Empty box for n=1 level (1)

- One electron in n=2 level (1)

MS6 (3 marks)

- Energy of a photon is proportional to the frequency of light (1)

- Wavelength is inversely proportional to frequency (1)

- Therefore, energy is inversely proportional to wavelength (1)

MS7 (4 marks)

- State symbols included: (s), (g) (1)

- Equation balanced: 2 moles of KCl react with 1 mole of O2 (1)

MS8 (4 marks)

- Correct substitution: E = -Rhc/n^2 (1)

- Correct units: R converted to J m^-1 (1)

- Calculation: E = -(1.097 x 10^7 J m^-1) x (6.63 x 10^-34 J s) x (3.00 x 10^8 m s^-1) / (3^2) = -3.03 x 10^-19 J (2)

MS9 (4 marks)

- Hydrogen: Lines are at very specific wavelengths (1)

- Metal: Lines are less distinct and appear as a band (1)

- Hydrogen: Fewer lines (1)

- Metal: More lines (1)

MS10 (4 marks)

- Electrons occupy fixed energy levels around the nucleus (1)

- Energy levels are quantized (1)

- Limitation: Cannot explain the shape of orbitals (1)

- Limitation: Does not account for the dual nature of electrons (1)