Chapter 7

Question 1

what are the 2 classes of objects

Answer 1

matter and electromagnetic radiation

Question 2

describe the characteristics of matter

Answer 2

-has both volume and mass
-has a defined position in space/time
-follows newton’s law

Question 3

describe the characteristics of electromagnetic radiation

Answer 3

• doesn’t have mass
• delocalized and propagated through waves
  -follows maxwell’s equations

Question 4

what’s the purpose of electromagnetic radiations

Answer 4

allows energy to travel through space

Question 5

what are the 3 characteristics of electromagnetic radiation

Answer 5

1) wavelength (lambda): distance between two peaks/bottoms in waves
2) frenquency (mu): amount of waves/cycles per sec that pass at a given point
3) speed (C): speed of light

Question 6

how are wavelenght and frenquency related

Answer 6

inversly proportional

Question 7

define waves

Answer 7

continuous repeated change/oscillation through matter or a physical field

Question 8

define light

Answer 8

a type of electromagnetic wave that contain oscillation through a magnetic field and that travels space

Question 9

true or false
Energy can only be lost/gained through multiple integers

Answer 9

true

Question 10

Whats Plank’s equation and its purpose

Answer 10

E=hv
gives us the electronic transiton of an electron

Question 11

Why is energy considered to be quantized

Answer 11

system can only transfert energy whole quanta/packets

Question 12

whats the photoelectric effect

Answer 12

when electrons are ejected fro a metal or other materials because light is shining on it.

Question 13

Fill the blank
Light has both propertie of — and —

Answer 13

wave and matter

Question 14

what is light’s duality

Answer 14

particle/wave duality

Question 15

True or false
energy has matter and matter has energy

Answer 15

true

Question 16

What two equation did De Broglie mix to fin the E of a photon

Answer 16

E=mc^2 and E=hv

Question 17

what’s a continuous spectrum

Answer 17

a spectrum that emits all wavelengths of light (rainbow)

Question 18

whats a line spectra

Answer 18

spectrum where only certain colors appear since only specific wavelengths are present
only certain energies are allowed for electrons.

Question 19

what are the 4 main concepts of the atomic spectrum

Answer 19

1) electrons move from orbit to orbit, but its easier for them to go from an outter shell to inner one
2) the difference/distance between shells is the wavelength
3) energy is lost when electron transition between shells, that energy is carried out by photon which emit light
4) diff wavelength = diff colors

Question 20

whats a ground state

Answer 20

lowest possible energy level (n=1), the closest to the nucleus and most stable since more attraction

Question 21

define the energy level postulate

Answer 21

electrons can only be associated to specific energy levels

Question 22

true of false
energy is absorbed when electrons move from outter shells to inner ones

Answer 22

false, the energy is omitted
for energy to be absorbed the electrons must move from inner to outer levels.

Question 23

what are the limitations of Bohr’s model

Answer 23

it only works for one elctron systems and doesn’t take in consideration the particle/wave duality of light

Question 24

what does the quantum mechanical model explain

Answer 24

it explain electrons according to the particle/wave duality

Question 25

what does shrodinger's equation gives us

Answer 25

gives us the probability of finding an electron in a specific region of space.

Question 26

what does the principal quantum number (n) describe and what is its possible values

Answer 26

n= size and energy of shell, the smaller the value= smaller orbit and energy values are positive integers above 0

Question 27

what does the angular momentum quantum number (l) describe and what is its possible values

Answer 27

l= distinguishes the different orbital shapes within an orbit values range form 0 to n-1 values associated to differentes shapes

Question 28

what does the magnetic quantum number (ml) describe and what is its possible values

Answer 28

distinguishes the different orientation of orbitals values: depends on values of l (-l..,0,..l)

Question 29

what does the spin quantum number (ms) describe and what is its possible values

Answer 29

distinguishes the 2 differentes possible spins of an e- values: -1/2 or 1/2

Question 30

define the pauli's exclusion principle

Answer 30

no two electrons can have the same set of four quantum number and each orbital can hold up to 2 electrons and they must be of opposite spin

Question 31

whats a polyelectronic atom

Answer 31

atom with more than one electron, they usually follow the spdf order

Question 32

why do s orbital have lower energy than d or p orbitals

Answer 32

the closer an orbital is to the nucleus the less energy it has as the attraction between the nucleus and the electrons is stronger therefor it penetrates more

Question 33

define the Aufbau principle

Answer 33

since protons are added pne by one to build up the elements the electrons are added similarly in the orbital, one by one

Question 34

define Hund's rule

Answer 34

the lowest energy configuration can only be obtained if we maximize the amount of unpaired electrons in orbitals

Question 35

where do we find valence electrons

Answer 35

in the outermost shell of the atom

Question 36

how does the atomic radius change and why

Answer 36

in a family the atomic radius increases as we go down since the number of orbit increases in a period, as we go towards the right, the radius decreases since the number of proton increase with creates more attraction and therefor more condensed

Question 37

true or false the atomic radius is the distance between two nuclei in a diatomic molecule

Answer 37

true

Question 38

whats the ionization energy and explain the trend across the periodic table

Answer 38

energy needed to remove the outermost electron to create a cation as we go down a family it decreases and increases as we go towards noble gases

Question 39

true or false the first ionization energy is the strongest

Answer 39

false its the weakest

Question 40

true of false ionization energy and electron affinity involves atoms in every state

Answer 40

false on gaseous state

Question 41

define electron affinity

Answer 41

energy needed to add an electron to create an anion thats more stable

Question 42

What trends describe electron affinity

Answer 42

from left to right, energy becomes more exothermic exothermic= electron added so energy released endothermic = electron removed so energy added

Question 43

whats the difference between paramagnetic substances and diamagnetic substances

Answer 43

P= weakly attracted to a magnetic field since has unpaired electrons D= not attracted to a magnetic field since has paired electron

Question 44

why are pair electrons not attracted to a magnetic field

Answer 44

since the paire electrons have opposite spins they cancel eachother and have no charge unlike an un paired electron

Question 45

whats the wavelength of microwaves and radar

Answer 45

microwaves= 10^-2 m radar= 10^-1 m

Question 46

what the wavelength of far infrared

Answer 46

10^-4 m

Question 47

between what wavelengths is the visible light spectrum

Answer 47

between 350 and 800 nm

Question 48

whats the wavelength of near infrared

Answer 48

10^-5 m

Question 49

whats the wavelength of uv

Answer 49

10^-7 and 10^-8 m

Question 50

whats the wavelength of x rays

Answer 50

between 10^-9 and 10^-11 m

Question 51

whats the wavength of gamma rays

Answer 51

10^-12 m

Question 52

state all waves in order of decreasing wavelength

Answer 52

radar-microwaves-far infrared-near infrared- visible- near uv- far uv- x rays- gamma rays

Question 53

what are the two atoms with an exception in their last orbitals

Answer 53

Cr: 4s^1 3d^5 Cu: 4s^1 3d^10

Question 54

define ground state

Answer 54

lowest energy configuration possible more stable