2.5 And 2.6

Question 1

Continuous spectra

Answer 1

Spectra where the radiation is distributed over all frequencies not just specific ranges

Example: blackbody radiation

Question 2

Is a lightbulb a continuous spectrum ?

Answer 2

Yes

Question 3

What do you see on the screen of the spectroscope for a continuous spectra ?

Answer 3

A rainbow

Question 4

Spectra are like what ? (Metaphor )

Answer 4

A bar code that uniquely specify the type of product

Question 5

Can wavelengths shorter than 400 nm be seen by humans?

Answer 5

No they are in the ultra violet part of the spectrum which is invisible to the human eye

Note: they are shown in purple on the emission spectra

Question 6

Emission lines

Answer 6

Bright line in a specific location of the spectrum corresponding to emission of light at a certain frequency

Question 7

Color equals what?

Answer 7

Frequency and wave length

Question 8

Can emission likes be altered for the same element (or whatever)?

Answer 8

No the intensity can be changed but not the color (frequency or wavelength)

Question 9

What are emission and absorption lines?

Answer 9

They are characteristic frequencies (wavelengths) at which matter absorbers or emits photons of electromagnetic radiation

Question 10

What kind of spectrum does the sun have ?

Answer 10

At first it appears to be continuous because of the rainbow but there are dark lines splitting the rainbow because some gases on the surface are being absorbed

Question 11

Absorption line

Answer 11

Dark line in an otherwise continuous bright spectrum where light within one narrow frequency range has been removed

Question 12

Absorption lines can be produced in a lab how?

Answer 12

By passing a beam of light from a continuous source through a cool gas

Question 13

Absorption and emission lines similar ?

Answer 13

Both contain the same information about the gas the absorbption lines occur at the same wavelengths as the emission lines when the gas is heated

Question 14

Which has more energy a low frequency photon or a high frequency photon?

Answer 14

High frequency photon

Question 15

Which color has a higher frequency blue or green?

Answer 15

I don’t now

Question 16

Kirchhoffs laws: rule 1

Answer 16

A luminous solid or liquid or a sufficiently dense gas, emits light of all wavelengths and so produces a continuous spectrum of radiation

Question 17

Kirchhoffs laws: rule 2

Answer 17

A low density hot gas emits light whose spectrum consists of a series of bright emission lines. These lines are characteristic of the chemical composition of the gas.

Question 18

Kirchhoffs laws: rule 3

Answer 18

A low density cool gas absorbs certain wavelengths from a continuous spectrum, leaving dark absorption lines in their place, superimposed on the continuous spectrum. These lines are characteristic of the composition of the intervening gas. They occur at precisely the same wavelengths as the emission lines produced by the gas at higher temperatures.

Question 19

When was helium discovered on earth?

Answer 19

1895