midterm

Question 1

what is a quantum ?

Answer 1

single indivisible unit

Question 2

nm to m

Answer 2

10 to the -9

Question 3

um to m

Answer 3

10 to the -6

Question 4

how is λ related to frequency ?

Answer 4

λ increases
frequency decreases

Question 5

how are E and f related

Answer 5

the same
E decreases f decreases

Question 6

what causes an emission spectrum

Answer 6

electron transfer from higher to lower energy level

Question 7

what causes an absorption spectrum

Answer 7

electrons move from lower to higher energy levels

Question 8

what is work function

Answer 8

minimum energy required of the photon to eject electrons from metal surface

Question 9

what is threshold frequency

Answer 9

minimum frequency of the photon that can release electrons from a metal surface

Question 10

name the series n= 1 to n=5

Answer 10

n=1 Lyman LBPBP
n=2 Balmer
n=3 Paschen
n=4 Brackett
n=5 Pfund

Question 11

photoelectric effect

Answer 11

when light radiation falls on a metal surface electrons are ejected
particle nature

Question 12

de broglie theory

Answer 12

wavelength = h/mu
combined particle and wave nature of electrons

Question 13

Plancks Equation

Answer 13

E =hf

Question 14

define orbital

Answer 14

particular area in an atom with 90% probability of finding electrons

Question 15

define orbit

Answer 15

circular path electron takes around nucleus

Question 16

node

Answer 16

space where probability of finding electrons is almost zero

Question 17

principal quantum number (n)?

Answer 17

signifies size of shell and energy of electron in that shell

Question 18

angular quantum number (l)

Answer 18

gives info about the shape of orbital
l =0 s orbital
=1 p orbital
=2 d orbital
=3 f orbital

Question 19

magnetic quantum number (ml)

Answer 19

signifies orientation of orbital
depend on l #

Question 20

spin quantum number

Answer 20

+ or - 1/2

Question 21

shielding effect

Answer 21

inner orbital electrons act as a shield between the nucleus and the outer orbital electrons. Due to this, the outer orbital electrons experience lesser nuclear attraction

Question 22

pauli exclusion principle

Answer 22

no two electrons can have same quantum number

Question 23

hunds rule

Answer 23

in degenerate orbitals the most stable electrons are ones with parallel spins

Question 24

aufbau principle

Answer 24

building up
one proton added to nucleus
one electron to orbitals