9/22 class notes

Question 1

what element is most abundant

Answer 1

hydrogen

Question 1

what info does light interaction with atoms and molecules provide

Answer 1

info about how electrons are arranged in an atom

Question 2

spectroscope

Answer 2

device that measures the different wavelengths of electromagnetic radiation coming from a light source

Question 3

gas emission lamps have what type of light lines

Answer 3

narrow (H, Ne, Na)

Question 4

spectrum from incandescent bulb

Answer 4

see a continuous spectrum of light, like sun

Question 5

spectrum of light from fluorescent light

Answer 5

bands of the spectrum

Question 6

what happens when electrons fall to become more stable

Answer 6

emits photons

Question 7

what makes electrons unstable

Answer 7

rising in n levels away from nucleus

Question 8

what type of energy and transition gap does blue light have

Answer 8

more photons of higher energy
-larger transition E gap

Question 9

what type of energy and transition gap does red light have

Answer 9

lower energy
-smaller transition energy gap

Question 10

when n level do Bahmer lines fall to

Answer 10

n=2

Question 11

what type of light is lyman lines like

Answer 11

UV

Question 12

what n level do lyman lines fall to

Answer 12

n=1

Question 13

what is the most stable n level

Answer 13

n=1

Question 14

what type of light is Pashen lines like

Answer 14

infrared

Question 15

what n level do Paschen lines fall to

Answer 15

n=3

Question 16

what happens to the charge of an electron as you pull it from the nucleus

Answer 16

becomes neutral

Question 17

what happens to the charge of an electron if it is bound to the nucleus

Answer 17

negative charge

Question 18

do energy gaps get larger or smaller as n increases

Answer 18

smaller

Question 19

limits and weaknesses of Bohr’s model

Answer 19

1)only works for hydrogen and hydrogen like ions (one nucleus and one electrons)
2)Heisenberg uncertainty principle: electrons don’t actually travel in orbits

Question 20

what is bohr’s model of an electron

Answer 20

-electrons only orbit
-electrons transition from one orbit to another
-if an electron goes from a closer orbit to further orbit: absorbs a photon, visa versa if it goes from further to closer

Question 21

Specifically what electron transitions are happening for the four lines? Without calculation you should be able to match the wavelength to the transition.

Answer 21

n=6 → n=2: violet, 410 nm wavelength
n=5 → n=2: blue, 434 nm wavelength
n=4 → n=2: green, 486 nm wavelength
n=3 → n=2: red, 656 nm wavelength
Violet has the largest gap between energy levels, and therefore the highest energy and shortest wavelength.