1.3.1-2 --> electron configuration ( emission Spectra)

Question 1

When do atoms of different elements give out light of a distinctive colour?

Answer 1

When an electric discharge is passed through a vapour of the element

Question 2

How can metals be identified?

Answer 2

By the colour of the flame produced when their compounds are heated in a Bunsen burner

Question 3

What does the full spectrum range from?

Answer 3

Low - energy radio waves to high- energy gamma rays

Question 4

At what speed do all electromagnetic waves travel at?

Answer 4

c = 3.0 x 10^8 m/s

Question 5

How can electromagnetic waves be distinguished?

Answer 5

By their different wavelengths?

Question 6

Different colours of visible light have different what?

Answer 6

Wavelengths

Question 7

What is a wavelength?

Answer 7

Distance between two crests or two troughs

Question 8

What is a frequency?

Answer 8

The number of waves that pass a particular point in 1s

Question 9

Wavelength and frequency rule?

Answer 9

The shorter the wavelengths the higher the frequency

Question 10

What equation are wavelength and frequency related by?

Answer 10

c = fλ

Question 11

What is white light?

Answer 11

A mixture of light waves of differing wavelengths or colours

Question 12

Where do we see white light?

Answer 12

When sunlight passes through a prism to produce a continues spectrum or when light is scattered through water droplets in the air

Question 13

What do atoms in visible light emit?

Answer 13

Infrared (IR) radiation (has longer wavelength than red light) and UV radiation (has shorter wavelength than violet light)

Question 14

How is an emission spectrum produced?

Answer 14

When an atom moves from a higher to a lower energy level

Question 15

What is a period?

Answer 15

Time for one cycle to occur

Question 16

How are electrons excited?

Answer 16

EM radiation can pass through atoms and some of the radiation absorbed is used to excite them

Question 17

How are emission line spectrums produced?

Answer 17

Produced by gasses when they are heated to a high temperature or if a high voltage is applied

Question 18

Why do the electrons fall back to the ground state when they are excited into a higher energy level?

Answer 18

Because the higher energy level is unstable

Question 19

What is a photon?

Answer 19

A packet of energy (light)

Question 20

Evidence for the Bohr model?

Answer 20

• Electrons move into high orbitals (energy levels) when atoms absorb energy
• Excited states are unstable and electrons will quickly fall back to lowest levels they can
• When electrons fall back to lower energy levels they give off light

Question 21

How many photons does each electron produce when they fall to lower energy levels?

Answer 21

One photon

Question 22

equation for electron and photon?

Answer 22

Delta Eelectron = Ephoton

Question 23

How can the electron change its energy?

Answer 23

By discrete amounts like a staircase

Question 24

What is the energy of the atom said to be?

Answer 24

Quantized

Question 25

What is the line Spectra crucial evidence for?

Answer 25

Quantization

Question 26

What would happen of the energy were not quantized?

Answer 26

The emission spectrum would be continues

Question 27

What does continues spectrum show?

Answer 27

Unbroken sequence of frequencies - Like spectrum of visible light

Question 28

Why does a line emission spectrum have only certain frequencies?

Answer 28

B/c its produced when atoms are excited and ions as they fall back to a lower energy level

Question 29

When would an atom absorb a photon?

Answer 29

An atom will only absorb a photon whose energy is equal to the energy difference in orbitals