Brainscape's Knowledge GenomeTM

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


See full index

as chemistry > Element of life . 1 & 2 > Flashcards

Element of life . 1 & 2 Flashcards

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

What is atomic number?

A

The number of protons in the nucleus of an atom.

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

relative mass of

protons

neutron

electron

A

1

1

very tiny

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

relative charge of :

protons

neutrons

electrons

A

+1

0

-1

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

location in atom:

protons

neutrons

electrons

A

in nucleus

in nucleus

around nucleus

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

what is mass number? and the equation

A

The total number of protons and neutrons in the nucleus of an atom

number mass = atomic number = number of nutrons

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

what is relative atomic mass (Ar) ?

A

is an average of relative isotopic masses, taking into account abundance.

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

what is the number of … in fluorine

neutron

proton

electron

A
  1. 19-9= 10
  2. 9 (atomic number)
  3. 9 ( same amount of proton)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are isotopes?

A

Isotopes are atoms with the same element but different number of neutrons. all atoms of an element have the same number of protons difference caused by different number of neutrons.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how does the mass spectrometry works? (in three bullet points )

A
  • sample atoms or molecules are ionised to positively charged cations
  • they pass through a drift region (vacuum) then hit a detector
  • these ions are separated according to their mass (m) to charge (z) ratios, m/z is the same as the mass ion detected together with their relative abundance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how do you work out relative mass when looking at a mass spectrum ?

using relative isotopic abundance

relative mass

A

Relative isotopic abundance = peak height of isotope or relative itensity/ total peak height

Relative mass = sum of relative abundance x mass number / 100

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

define nuclear fusion:

and the condition

A
  • The process by which two light atomic nuclei fuse together forming a single heavier nucleus of new element, releasing enormous quantities of energy.
  • two nuclei has to be very close together
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the equation of the fusion of different isotopes of hydrogen?

A

give the example with H:
(photo example)

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

write a nuclear equation for the fusion of a ( image ) nucleus

what are the rules when solving the problem

A
  • ignore the bit in the picture about what reaction it is
  • also neutrons only need to be included if numbers don’t add up
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In stars, reactiob called the “ triple alpha process” occurs where three helium nuclei fuse together.
- write a nuclear equation for this process

A

3 4/2 He > 12/6 C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What conditions are needed for nuclear fission? why

A

High temperature or/and pressure to provide the energy needed to overcome the repulsion between the 2 positive nuclei.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is the nuclear symbol for a neutron ?

A

1 n
0

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is spectroscopy ?

A

The study of how light and matter interact by usuing uses IR, visible and UV light.

18
Q

why do we analyse electromagnetic radiation in a characteristic way?

A

so you can identify a substance or find information about it, as its structure and the way atoms are held together.

19
Q

what is emissiion spectrum and describe the appearance :
-describe the line

A
  • element or chemical compound is the speatrum of freuqencies of electromagnetic raditios
  • consits of coloured of coloured lines on a black background
  • The lines become closer at higher frequencies
20
Q

Explain the formation of an emission spectrum

A
  • electrons in the ground state absorb energy
  • This promotes them to a higher energy level - exicted state
  • electrons then drop back down to lower energy levels. The energy lost (/_\ E) us emitted as a photon of light
  • different energy gaps produce photons of different frequencies
  • this produces different coloured bands on the emission spectrum
21
Q

what is a photon and quantised mean ?

A
  • quanta of energy in the form of electromagnetic radiation
  • energy that can only take particular values ( quanta )
22
Q

what is absorption spectrum and describe the appearance

A
  • a spectrum of electromagnetic radiation transmitted through a substance, showing darklines due to absorption at specific wavelengths.
  • If white light is passed through a sample of vaporised atoms, an absorption spectrum is seen
  • shown by black lines on a rainbow background (showing all colours of visible light)
23
Q

how are atomic absorption spectra formed ?

A
  • Electrons in the ground state absorb protons of light
  • the energy from these photons causes the electrons to be excited to higher energy levels
  • the electrons drop back down to the ground state and photon/ light is emitted.
  • light of the frequency doesn’t pass through the sample ( as it’s absorbed ) so a black line is seen in the spectrum
24
Q

why do the lines of emission/absorption spectra get closer together at higher frequencies?

A
  • Higher frequency lines are caused by translations of electrons with large energy needed (/_\ E) values
  • these are prodcued from translations from higher energy levels
  • higher energy levels are much closer together than lower energy levels
  • translations from adjacent energy levels will have similar /_\E values and hence produce light of similar frequencies
25
Q

compare the wavelength and frequency of red and blue visible light.

A
  • red : lower frequency, longer wavelength
  • blue : higher frequency, shorter wavelength
26
Q

what is the theory of light ?

A
  • a wave of light travels the distance between two points in a certain time it doesnt matter what kind of light it is the same for all kinds of light and electromagnetic radiation.
  • value = 3.00x10^8 ms^-1
27
Q

what is the euqation of speed of light with unit :

A

speed of light (c) (ms-1) = wavelength (m) x frequency (v) (s-1)

28
Q

what is the particle theory of light ?

A

The energy of the photons is related to the position of the light in the electromagnetic spectrum eg. photos with energy 3x10-19 ( J )

29
Q

what is the equation to find energy of a photon (E) ?

A

energy of a photon E (J) = Plack constant h (Js-1) x frequency v (s-1)

30
Q

Give Bohr’s explanation in absorbing and emitting

A
  • when an atom is excited, electrons jump into higher energy levels. which later they drop back into lower levels, emitting the extra energy as electromagnetic radiation and giving off an emission spectrum
  • light has been absorbed by the atoms = electrons have been raised to higher levels without them dropping back again.
31
Q

what were the main points of Bohr’s theory ?

A
  • The electron in the hydrogen atom exits only in certain definite energy levels or electron shells.
  • a photon of light is emitted or absorbed when the electron changes from one energy level to another energy
  • the energy of the photon is equal to the difference between the two energy levels /_\ E
  • Since E= hv it follows that the frequency of the emitted or absorbed light is related to /\E by /\E = hv
32
Q

Describe the emission spectrum figure:

A
  1. each rings represent the energy levels of the electron in the hydrogen atom
  2. the further away from nucleus an electron is = the higher the energy level
  3. number 1 = lowest level
  4. larger the energy gap (energy change) between the two levels = the higher the frequency of electromagnetic radiation emitted
33
Q

describe how to draw arrows to show the orgin of 2 lines on its absorption spectrum :

A
  1. at least three horizontal lines with upper gaps smaller than lower ones
  2. 2 upward arrows connecting energy levels (different combination)
  3. Y-axis labelled “energy”
34
Q

Describe how to carry out a flame test :

A
  1. Dip wire loop into HCl (cleaning
    + adhesion)
  2. Dip into solid sample
  3. hold in blue bunsen flame colour obserevd
35
Q

what flame colour is produced by burning a splint soaked in a solution of lithium chloride ?

A

Bright red

36
Q

What flame colour is produced by burning a splint soaked in a solution of sodium chloride?

A

Yellow

37
Q

What flame colour is produced by burning a splint soaked in a solution of potassium chloride ?

A

Lilac

38
Q

What flame colour is produced by burning a splint soaked in a solution of calcium chloride ?

A

Brick red

39
Q

What flame colour is produced by burning a splint soaked in a solution of barium chloride ?

A

Green

40
Q

What flame colour is produced by burning a splint soaked in a solution of copper chloride ?

A

Blue-green

41
Q

What is the order of wavelenght of Infared radiation, visible and ultraviolet ?

A
  • IR has the greatest wavelength then visible then ultraviolet
  • reciprocal relation between frequency + wavelength

as chemistry (10 decks)

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