Inorganic Chemistry 1 - Electromagnetic Spectrum and Atomic Spectra

Question 1

Why is Electromagnetic radiation said to have a dual nature?

Answer 1

because it can be described as a wave and a particle

Question 2

The energy of one mole of photons is given by the equation:
E=Lhf and c = fλ
E=?
L=?
h=?
f=?
c=?
λ=?

Answer 2

E = energy, measured in kilo-joules per mole (kJ mol-1)
L = Avagadro’s Constant: the number of particles in 1 mol - (6.02x10^23)
h = Planck’s Constant: a number that relates the energy of a photon to its frequency (6.63x10^-34)
f = frequency of a photon - measured in Hz or S-1 (same thing).
c = speed of light (3x10^8m/s)
λ = wavelength (the symbol is called lambda), length of one wave, measured in metres (m)

Question 3

When electromagnetic radiation is absorbed or emitted by matter, it behaves like…

Answer 3

a stream of particles

Question 4

These particles are known as ___.

Answer 4

photons

Question 5

A photon carries quantised energy, proportional to the ___ of radiation.

Answer 5

frequency (low frequency = long wavelength = low energy)

Question 6

When a photon is absorbed or emitted, energy is gained or lost by ___ within the substance.

Answer 6

electrons

Question 7

An absorption spectrum is produced by directing ___ ___ at an atomised sample.

Specific wavelengths of EMR are absorbed when…

Answer 7

electromagnetic radiation.

electrons are promoted to higher energy levels

Question 8

An absorption spectrum looks like a rainbow with ___ lines, which represent the ___ of light by ___ within the substance.

Answer 8

black, absorption, electrons

Question 9

The light energy that is emitted by an atom produces a series of ___, representing the different energy levels within an ___.

Answer 9

lines, atom

Question 10

An emission spectrum is produced when a substance is ___, causing electrons to become ___.

Answer 10

heated, excited

Question 11

The excited electrons then…

Answer 11

drop to lower energy levels, emitting a photon of light with a frequency that corresponds to the energy difference between the two levels

Question 12

Each atom in a sample can produce a unique ___ and ___ spectra that can be used to ___ the element.

Answer 12

absorption, emission, identify

Question 13

An emission spectrum is black, with coloured ___ representing the ___ of light that were emitted.

Answer 13

lines, photons

Question 14

Are the lines in emission and absorbtion spectra the same for any given element?

Answer 14

yup

Question 15

In atomic spectroscopy, the concentration of an ___ within a sample is proportional to the ___ of light emitted or absorbed.

Answer 15

element, intensity