EL2 - Atomic Spectra

Question 1

What are the characteristics of the ultraviolet side of the electromagnetic spectrum?

Answer 1

High frequency
Short wavelength
High energy

Question 2

What are the characteristics of the infrared side of the electromagnetic spectrum?

Answer 2

Low frequency
Long wavelength
Low energy

Question 3

What has a lower energy than infrared?

Answer 3

Radiowaves

Question 4

What has a higher energy than ultraviolet?

Answer 4

X-rays, then Gamma rays

Question 5

What is the name for the study of how light and matter interact?

Answer 5

Spectroscopy

Question 6

What are the two theories explaining light, neither of which does so fully?

Answer 6

Wave theory and Particle theory.

Question 7

λ (lambda) = ?

Answer 7

Wavelength (m)

Question 8

As wavelength increases, frequency…

Answer 8

Decreases

Question 9

v = ?

Answer 9

frequency Hz or s-1

Question 10

c = ?

Answer 10

The speed of light

Question 11

What is the equation triangle for speed of light, frequency and wavelength?

Answer 11

C

 λ                   v

Question 12

What is the equation for energy in the particle model of light?

Answer 12

E = hv

Question 13

What is Bohr’s theory?

Answer 13

-electrons become excited when they gain energy
- they can lose this energy again
- when they lose it they emit radiation
- the frequency of this radiation is fixed so electrons must exist in definite energy levels
- when they move from a higher to lower energy level they emit photons.
The energy of these photons is equal to the difference between the two energy levels

Question 14

What would a hydrogen emission spectrum look like if electrons didn’t only exist in fixed energy levels?

Answer 14

Instead of specific frequencies, every frequency would be observed

Question 15

What is a Quanta?

Answer 15

A fixed quantity of energy

Question 16

Electrons can move from ____ to _____ energy levels. Emitting photons of a particular energy, which corresponds to the energy gap between the 2 levels.

Answer 16

Higher to Lower

Question 17

The higher frequencies on the emission spectra correspond to …..

Answer 17

The largest energy gaps

Question 18

What is the name for the hydrogen emission spectra

Answer 18

The Lyman Series

Question 19

What is an absorption spectra?

Answer 19

It shows all the frequencies of radiation expect any being absorbed.

Question 20

On an absorption spectra, absorbed frequencies will appear as _____

Answer 20

Black lines on a coloured background

Question 21

For a particular element the frequencies of these black lines correspond to those observed on the ….

Answer 21

Emission spectra

Question 22

Why do some elements have characteristic flames?

Answer 22

Because the energy of photos emitted corresponds to a wavelength on the visible spectrum.

Question 23

What are the flame colours of - 
Lithium 
Sodium
Potassium 
Calcium 
Barium 
Copper

Answer 23

Lithium - bright red 
Sodium - yellow 
Potassium - lilac 
Calcium - brick red 
Barium - apple green
Copper - blue green