Radiation and Spectra

Question 1

The energy associated with a single photon is given by

Answer 1

E=hf or E=hc/λ

Question 2

The energy associated with one mole of photons is given by

Answer 2

E=Lhf or E=Lhc/λ

Question 3

Electromagnetic radiation is said to have a ____nature

Answer 3

dual

Question 4

E and f are

Answer 4

proportional (E=f)

Question 5

When energy is transferred to atoms, electrons within the atoms may be

Answer 5

promoted to higher energy levels

Question 6

An atom emits a photon of light energy when

Answer 6

an excited electron moves from a higher energy level to a lower energy level

Question 7

Describe emission spectroscopy

Answer 7

High temperatures are used to excite the electrons within atoms. As the electrons drop to lower energy levels, light is emitted

Question 8

Describe absorption spectroscopy

Answer 8

Electromagnetic radiation is directed at an atomised sample. radiation is absorbed as electrons are promoted to higher energy levels.

Question 9

In atomic spectroscopy the concentration of an element within a sample is

Answer 9

related to the intensity of light absorbed

Question 10

Explain in terms of energy levels why coloured light is emitted

Answer 10

The difference in the energy levels
corresponds to the light emitted

Question 11

Why is there a series of discrete lines?

Answer 11

different electron transitions