Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

hl chemistry > unit 1 > Flashcards

unit 1 Flashcards

You may prefer our related Brainscape-certified flashcards:
Chemistry 101 flashcards AP® Chemistry flashcards Periodic Table flashcards Organic Chemistry 101 flashcards
1
Q

what is an element

A

pure substance made of 1 type of atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is a compound

A

pure substance made of 2+ elements chemically bonded (ratio of elements must always be the same)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

homogenous mixture

A

uniform composition + properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

heterogeneous mixture

A

non-uniform composition + properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what’s fractional distillation

A

heating up mixture (of liquids) until 1 or more “fractions” of mixture vaporize

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what’s chromatography

A

solutes (stationary) are distributed by liquid/gas (mobile), different solutes = different distribution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what’s gel electrophoresis

A

electrical current is applied to mixture separating charged and uncharged components

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

why does temperature stay the same during phase changes?

A
  • kinetic energy remains constant
  • energy is used to overcome attractive forces between atoms + disrupt solid lattice
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

particle theory of matter

A
  1. all matter is made of particles
  2. all particles of one substance are identical
  3. particles of matter are in constant motion
  4. particles have spaces b/w them
  5. there are attractive forces b/w particles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

sublimation

A

solid –> gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

deposition

A

gas –> solid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

ionization

A

gas –> plasma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

de-ionization

A

plasma –> gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are endothermic processes? give examples

A
  • process requiring/absorbing energy
  • feels cold to the touch
    ex. evaporation, melting, sublimation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are exothermic processes? give examples

A
  • process producing/releasing energy
  • feels hot to the touch
    ex. freezing, condensation, deposition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is kinetic molecular theory(KMT)?

A
  • model used to explain/predict behaviour of gases at microscopic level
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what postulate/assumptions is the KMT based on?

A
  1. gases are made of tiny particles separated by large distances, most is empty space
  2. gaseous particles are constantly moving in straight lines in random directions
  3. gaseous particles undergo elastic collisions w/ each other + container. loses no kinetic energy
  4. no force of attraction b/w gaseous particles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how do gases act at high temp, low pressure?

A
  • forces b/w gas molecules are minimized
  • high degree of separation
  • adheres to ideal gas model
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how do gases act at low temp, high pressure?

A
  • particles move slower
  • distance b/w particles decrease
  • intermolecular attractions become significant, gas can liquefy
  • gas departs from ideal gas behavior, exhibits real gas behavior
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what does temp measure

A

the average kinetic energy of particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what does the kelvin temperature scale represent

A
  • the relationship b/w temperature and volume within gases (experiments showed that changing temp of gas changes its volume)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what temperature is absolute zero?

A

-273.15C, 0K, -459F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what is water’s melting/freezing point?

A

0C, 273.15K, 32F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is water’s boiling point?

A

100C, 373.15K, 212F

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

extrapolation

A
  • estimation of extension of graph/values, based on existing trends
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is the atomic mass unit (AMU)

A
  • relative unit of measure of atomic/molecular weights
  • equal to one-twelfth of the mass of an atom of carbon-12(standard)
  • around 1.67 x 10^-27
27
Q

what are isotopes

A
  • atoms with the same atomic # but different atomic masses (same # of protons, different # of neutrons)
28
Q

all isotopes have ____ chemical properties, but _____ physical properties

A

same, slightly different

29
Q

radioactive decay

A
  • some isotopes are stable while others are not (too many/few neutrons) –>go through nuclear decay
  • becomes radioactive (radioisotopes)
  • leads to spontaneous transformation from 1 isotope/element into another
30
Q

relative atomic mass

A
  • mass of element on periodic table
  • average mass of all isotopes of an atom present on earth
31
Q

properties of EM spectrum

A
  1. all EM radiation travels at the same speed in a vacuum (3.00 x 10^8m/s)
  2. as wavelength of radiation increases, frequency decreases
  3. sunlight and white light produce entire ROY G BIV spectrum
  4. amplitude of wave represents intensity (higher amplitude = greater intensity)
32
Q

how are atoms excited

A

when EM radiation is passed through atoms, some is absorbed and used to excite atoms into higher energy

33
Q

absorption spectrum

A

when wavelengths of light are absorbed by atoms, showing up as dark bands on ROY G BIV spectrum

34
Q

emission line spectrum

A

when high voltage is applied to the gas, the emission line spectrum is produced
-distinct lines at specific wavelengths ocrrosponding to different elements/compounds

35
Q

emission spectrum

A

refers to spectrum of light emitted by a source
- includes both conitnuous and line spectra

36
Q

ground state (stationary state)

A
  • electrons occupying fixed circular orbits around nucleus
  • do not emit energy
37
Q

how do electrons go from ground state to excited state?

A
  • emitting or absorbing specific amount of energy thats exactly equal to the difference b/w 2 states
38
Q

electrons ____ energy when going from excited state to ground state and ____ energy when going from ground state to excited state

A

release, absorb

39
Q

photons of UV radiation have ____ energy than that of infrared radiation

A

more

40
Q

relationship between photons and energy

A
  • energy of photon = frequency of radiation
  • energy of photon of light = change in energy in atom
41
Q

Planck equation

A

equation: change in electron energy = planck constant x frequency (E=hv or E=hf)

42
Q

reds have the ____ photon energy and violets have the ____ photon energy

A

lowest, highest

43
Q

reds have the ___ wavelength and violets have the ____ wavelength

A

longest, shortest

44
Q

hydrogen emission spectra

A

red (656nm), blue-green (486nm), blue-violet (434nm), violet (410nm)

45
Q

what does energy level 1 produce?

A

ultraviolet light

46
Q

what does energy level 2 produce?

A

visible light

47
Q

what does energy level 3+ produce?

A

infrared light

48
Q

what did prince louis de broglie do?

A
  • PhD thesis: if things believed to be particles (electrons, cars) could act like waves
  • no one took his idea seriously until einstein read them and agreed
  • came up with the formula: wavelength = h/mv, allowing the calculation of wavelength of moving particle (m=mass, v=velocity)
49
Q

what must happen for an object to have a wavelength

A

it must be moving

50
Q

young’s double slit experiment

A
  • a light source illuminates barrier with 2 slits
  • 2 beams of light can be seem from slits
  • as light waves spread, alternating dark and light beams can be seen
  • evidence that light behaves as a wave
51
Q

davisson-germer experiment

A
  • shot elections at crystal sample of nickel
  • spaces b/w nickel atoms are similar in size to wavelength of moving electrons
  • on other side of nickel, electrons (acting as waves) hit screen and formed interference pattern
52
Q

the uncertainty principle

A
  • we cannot know both the location and momentum of an electron, measuring one blurs the other
53
Q

schrodinger’s wave mechanical model

A
  • proposed an equation that instead of being able to calculate exact location of electron, gives probability of finding electron in a specific place around nucleus
54
Q

what is an atomic orbital

A

region around an atomic nucleus where this is a 90% probability of finding an electron

55
Q

order of sublevels

A

s<p<d<f

56
Q

quantum numbers

A
  • used to describe position of electron
  • 4 quantum numbers
  • pauli’s exclusion principle states no two electrons have the same set of quantum numbers
57
Q

principle quantum number

A
  • represented by n
  • describes size + energy of orbital
58
Q

secondary quantum number(angular momentum)

A
  • represented by l
  • describes number of sub levels
  • describes shape of each orbital
  • corresponds to s,p,d,f
    l = n -1
59
Q

magnetic quantum number

A
  • represented by m(subscript) l
  • describes number of orbitals and orientation within a subshell
60
Q

spin quantum number (fourth quantum number)

A
  • represented by m(subscript) s
  • shows direction of electron spin
  • arrows used in orbital diagrams
61
Q

aufbau principle

A

electrons occupy lowest energy orbital of lowest energy level first

62
Q

pauli’s exclusion principle

A

no two electrons may have same set of quantum numbers therefore electrons in same orbital must have opposite spins

63
Q

hund’s rule

A

distribute electrons in orbitals of equal energy so that no electron pairing occurs until needed

64
Q

what are degenerate orbitals?

A

orbitals of equal energy (ex. 2px, 2py, 2pz)

hl chemistry (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions