Electromagnetic radiation and atomic spectra

Question 1

What is the electromagnetic spectrum in order of highest to lowest energy and decreasing wavelength

Answer 1

gamma rays, X-rays, ultraviolet radiation, visible light, infrared radiation, and radio waves
Microwaves (like the ones used in microwave ovens) are a subsection of the radio wave

Question 2

All electromagnetic radiation travels at the same what?

Answer 2

Velocity

Question 3

What is wavelength and what is it measured in?

Answer 3

It is the distance between adjacent crests (or troughs) and is measured in nanometres 1 nm = 10‑9 m

Question 4

What is frequency and what is it measured in?

Answer 4

It is the number of wavelengths that pass a fixed point in one unit of time, usually one second
Hz or s‑1

Question 5

What happens if we increase the frequency in the equation
c=f×λ

Answer 5

the wavelength decreases

Question 6

How to create a continuous spectrum

Answer 6

When a beam of white light is passed through a prism or from a diffraction grating onto a screen

Question 7

What shows up as dark lines on the continuous spectrum on an absorption spectrum

Answer 7

If a beam of continuous radiation like white light is directed through a gaseous sample of an element, the radiation that emerges has certain wavelengths missing.

Question 8

Explain what an emission spectrum is

Answer 8

an emission spectrum of a sample is produced by measuring the intensity of light emitted at different wavelengths;
photons of light energy are absorbed by atoms when electrons move from a lower energy level to a higher one;

Question 9

Explain absorption spectra

Answer 9

atomic emission spectra are made up of lines at discrete frequencies;
in emission spectroscopy, high temperatures are used to excite the electrons within atoms - as the electrons drop to lower energy level, photons are emitted;

Question 10

What is a photon?

Answer 10

a photon carries quantised energy proportional to the frequency of the radiation

Question 11

absorption or emission of electromagnetic radiation causes it to behave more like what?

Answer 11

a stream of particles called photons

Question 12

How to create an absorption spectrum

Answer 12

an absorption spectrum is produced by measuring how the intensity of absorbed light varies with wavelength

Question 13

atomic emission spectroscopy and atomic absorption spectroscopy are used to identify and quantify what?

Answer 13

atomic emission spectroscopy and atomic absorption spectroscopy are used to identify and quantify the elements present in a sample

Question 14

the concentration of an element within a sample is related to what?

Answer 14

the intensity of light emitted or absorbed