S.1.3.1 and S.1.3.2 Emission Spectra

Question 1

Continuous spectrum

Answer 1

Contains light of all wavelengths and all frequencies

Question 2

Line spectrum

Answer 2

Contains selected frequencies; gaps in the spectrum

Question 3

Spectrometry

Answer 3

Light interacting with matter

Question 4

Light

Answer 4

All waves on the electromagnetic spectrum (waves of energy)

Question 5

What does adding energy to electrons do?

Answer 5

Allows electrons to overcome the electrostatic attractive forces and move to the next shell

Attractive forces keep electrons as close to the nucleus as possible

Question 6

Emission spectrum

Answer 6

A hot gas is placed in front of a prism and produces a line spectrum on a black background

Question 7

Absorption spectrum

Answer 7

A cold gas is placed between a prism and a light source and produces a line spectrum with gaps on the background of a continuous spectrum

Question 8

Electromagnetic radiation

Answer 8

Emitted in different forms of differing energies; travels at the speed of light; can be distinguished by different wavelengths

Question 9

Frequency

Answer 9

Number of waves that pass a particular point in a second

Question 10

Relationship between frequency and wavelength

Answer 10

Inversely proportional

Question 11

Electron in the excited state

Answer 11

Unstable, immediately returns to ground state by giving out energy in the form of electromagnetic radiation

Question 12

Photon

Answer 12

Packet of energy released for each electron transition between energy levels

Question 13

IMPORTANT!

No answer needed

Answer 13

Gases produce a characteristic emission line spectrum when heated to a high temperature

Question 14

Energy of photon

Answer 14

Proportional to the frequency of the radiation

E = hf

Question 15

Quantization

Answer 15

The idea that electromagnetic radiation comes in discrete packets (quanta)

Question 16

IMPORTANT!

No answer needed

Answer 16

Electrons will absorb and release only the exact energy required to move between allowable energy states

Energy is quantized

An electron moving between two energy levels always absorbs and releases the same, discrete amount of energy

Question 17

What is the evidence for quantization?

Answer 17

Line (not continuous) spectra for each element

Question 18

Evidence for the structure of the atom

Answer 18

• Atoms emit photons of certain (not continuous) energies; these energies correspond to certain frequencies, telling us the electrons are located on energy levels
• Energy is quantized (line spectra)

Question 19

Convergence

Answer 19

Shells converge at higher frequencies (farther away from the nucleus)

Question 20

What happens as shells converge?

Answer 20

They form a continuum wherein no extra energy is needed for the electrons to move between shells (ionized atom)

Question 21

UV released

Answer 21

Any higher shell to the ground state

Question 22

Visible light released

Answer 22

Any higher shell to the second shell

Question 23

Infrared waves released

Answer 23

Any higher shell to a shell n > 2

Question 24

IMPORTANT!

No answer needed

Answer 24

Electrons do not always immediately return to the ground state after being excited once and may move to a higher shell if given more energy