Brainscape's Knowledge GenomeTM

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


See full index

chemistry year 11 > module 1 > Flashcards

module 1 Flashcards

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

Describe the properties of mixtures

A
  • can be separated by physical means
  • composition varies
  • set of properties varies
  • comprises two or more pure substances
  • made of different types of particle groups
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

describe the properties of a pure substance

A
  • can’t be separated by physical means
  • constant/definite composition
  • fixed set of properties
  • made of one type of particle group
  • can be separated by chemical means
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the types of mixtures

A

homogeneous and heterogeneous

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

what are the properties of homogenous mixtures

A
  • one visible layer
  • uniform in all parts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what are the properties of heterogeneous mixtures

A
  • not uniform in all parts
  • more than one visible layer
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

describe the three types of homogeneous mixtures

A
  1. Alloy = solidified metal mixture that had other elements dispersed through it when molten (e.g. bronze, steel, brass)
  2. solution = solute dissolved in a solvent
    - clear/transparent
    - one layer
    - aqueous solution - the solvent is water
  3. Colloid = large molecules are evenly spread out through another substance, usually a liquid; the large molecules do not settle over time
    - one layer
    - opaque
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are the two types of pure substances

A

element and compound

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

what is an element

A

made of one type of atom in particle group

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

what is a compound

A
  • made of two or more
    different types of
    atoms in each particle
    group
  • made of two or more
    elements, chemically
    joined
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is a suspension (heterogeneous mixture)

A

Suspension = mixture where combined substances do not dissolve in one another but form layers quickly
- Two or more layers of substances
- May be clear, translucent or opaque

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

list the types of separation techniques

A
  • sieving
  • filtration
  • sedimentation
  • separation by funnel
  • evaporation
  • distillation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

outline sieving as a separation technique

A

uses a metal net to separate small
particles from large particles, e.g. gravel from sand

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

outline filtration as a separation technique

A

uses a special membrane with fine
holes to allow liquids through but not
undissolved solids,
residue = solid caught by filter
filtrate = liquid that passes through filter

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

outline sedimentation as a separation technique

A

Sedimentation allows time for
denser undissolved solids to settle
to the bottom of a container

Accompanied by decantation,
which is the careful pouring out
of the top layer of liquid

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

outline evaporation as a separation technique

A

Evaporation uses heat to boil off
the liquid part of a solution, leaving
the solute behind

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

outline distillation as a separation technique

A

Distillation is evaporation with an
added step to capture and condense
the boiled liquid in a second
chamber

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

outline separation by funnel as a separation technique

A

Separating funnel is used to separate immiscible liquids after sedimentation

Each layer is drained into a different container

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the difference between a molecule and a lattice

A

Molecule = a discrete group of atoms chemically joined

Lattice = a regularly repeating arrangement of atoms in three dimensions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how can you classify elements based on physical properties

A
  • lustre
  • ductility
  • malleability
  • melting point
  • boiling point
  • electrical conductivity
  • heat conductivity
  • density
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are the physical properties of metals

A
  • lustrous
  • usually high melting point
  • usually high boiling point
  • high ductility
  • high malleability
  • high density
  • high electrical conductivity
  • high heat conductivity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are the physical properties of semi-metals

A
  • usually lustrous
  • high melting point
  • high boiling point
  • usually no malleability
  • usually no ductility
  • low electrical conductivity
  • variable heat conductivity
  • moderate to low density
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

what are the physical properties of non-metals

A
  • dull
  • usually low melting point
  • usually low boiling point
  • very low malleability
  • very low ductility
  • very low heat conductivity
  • very low electrical conductivity
  • low density
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how can you classify elements based on chemical properties

A
  • reactivity with oxygen in the air
  • reactivity with water
  • reactivity with acid
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is an atom

A
  • the smallest particle of matter that exists by itself in nature.
  • the smallest unit of an element that has all the properties of that element.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

describe the bore model of an atom

A

According to the Bohr model of the atom:
- electrons can only move with fixed amounts of energy, called energy levels
- electrons with the same energy level move in the same circular orbit around the nucleus
- orbits closer to the nucleus contain lower energy
- each energy level has a maximum number of electrons it can contain, given by 2n^2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

what is an isotope

A

atoms of the same element have different numbers of neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how do you calculate relative atomic mass

A

Relative atomic mass = (Mass no. of Isotope 1 x % abundance) + (Mass no. of Isotope 2 x % abundance)/100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

outline the purpose of flame tests

A

A flame test seeks to identify the
metal present in a substance by the
colour displayed when a small
sample of the substance is placed in
a blue Bunsen flame.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

explain atomic emission spectroscopy

A
  • White light passed through a prism is spread out into different colours
  • Source of light can be: Metal sample in a Bunsen flame orGas discharge tube with electricity
  • The emitted light is passed through a
    vertical slit, then spread out by a prism
  • This produces coloured, vertical lines on a black strip, called emission spectrum
  • Each element has a unique emission
    spectrum
  • Atoms of the same element produce the same emission spectrum
30
Q

explain the evidence for the Bohr model

A
  • According to the Bohr model of the
    atom, electrons can only move with
    fixed amounts of energy, called
    energy levels.
  • When an atom is given energy (by
    heat or electricity), its electrons
    gain energy and jump from a lower
    to a higher energy level.
  • After a short time, the electrons fall
    back down to their original energy
    level and release energy as light.
  • The packet of energy corresponds
    to a wavelength of light (colour).
  • The same emission spectrum from
    the same element supports Bohr’s
    model that electrons can only move
    between fixed energy levels.
31
Q

what are the limitations of the Bohr model

A
  • does not explain why the maximum amount of electrons in each energy level is 2n^2
    -Does not explain why elements in Periods 4 to 7 can place electrons in an ‘outer’ energy level before an ‘inner’ energy level is fully filled,
32
Q

explain the Schrödinger model

A
  • Arises out of quantum mechanics
  • Major energy levels, a.k.a shells, contain sub-shells of similar energy levels; these are referred to as s, p, d, f.
  • Each sub-shell is associated with 3D regions around the nucleus where its electrons are probably found; these regions are known as orbitals
  • Each orbital can contain up to 2 electrons of opposite spin (Pauli exclusion principle)
33
Q

outline the 3 rules of the Schrödinger model

A
  • The lowest energy orbitals are always filled with electrons first (Aufbau principle)
  • Every orbital in a subshell must first be filled with one electron with the same spin before an orbital can be filled with a second electron (Hund’s rule)
  • At higher subshells, there are exceptions to this because of the Aufbau principle.
  • The second electron in an orbital must have the opposite spin to the first electron
    (Pauli exclusion principle simplified).
34
Q

draw both electron configuration diagrams from the Schrödinger model

A
35
Q

what are radioisotopes

A

Some isotopes are unstable, i.e. they
will spontaneously break down over
time.
- Unstable isotopes are called
radioisotopes because, when they
break down, they send out particles
or energy from their centre along
radial lines.
- What is emitted from the centre is
known as radiation.

36
Q

which isotopes are unstable

A
  • isotopes are unstable when they exist outside of the zone of stability
    The Zone of Stability is defined as:
  • Atomic number < 83
  • neutron : proton ratio that is 1:1 for
    atomic number 1-20
  • neutron : proton ratio that is 1.3:1
    for atomic number 21-50
  • neutron : proton ratio that is 1.5:1
    for atomic number 51-80
37
Q

what are the three types of radiation

A
  • alpha particle
  • beta particle
  • gamma ray
38
Q

describe alpha particle radiation

A
  • it is like a helium nucleus (emits 2 neutrons and 2 protons0
  • It has a charge of +2
  • it has low penetration (stopped by a piece of paper
  • it is emitted when radioisotope lies beyond atomic number 82 and is very heavy
39
Q

describe beta particle radiation

A
  • it emits an electron
  • change of -1
  • moderate radiation (stopped by 0.5mm of lead)
  • emitted when radioisotope lies above zone of stability and a neutron converts
    to a proton and electron
40
Q

describe gamma ray radiation

A
  • electromagnetic radiation
  • no charge
  • high penetration (stopped by 5cm of lead)
    -emitted with an alpha or beta particle
41
Q

describe how you write nuclear equations

A
  • Whenever radioisotopes emit alpha or beta particles, the composition of their nuclei change with an alteration in the number of protons.
  • This MUST mean that the atom has changed from one element to another.
  • Nuclear equations communicate what happens to nuclei in a nuclear reaction.
  • An equation must balance the mass number and atomic number
42
Q

what is a half life

A
  • The rate of decay of a radioisotope is
    proportional to the amount of
    radioisotope present.
  • It is measured by a term called half-life,
    which is the time taken for half of the
    radioisotope to decay.
  • A long half-life means that decay is slow and radiation is emitted for a long
    period
  • A short half-life means that decay is
    rapid and the total amount of radiation is emitted in a burst.
43
Q

what is periodicity

A

Periodicity refers to the pattern of similar properties recurring at intervals when examining elements in increasing atomic number.

44
Q

what are the trends in electron configuration

A
  • Elements in the same group have similar electronic configurations, especially for their valence shell.
  • More energy shells are added going down a group.
  • Different sub-shells are filled going across a period.
45
Q

what is core charge

A
  • Core charge = the no. of protons – the no. of electrons in inner shell(s)
  • Core charge is a measure of how strongly the nucleus pulls on the outer shell electrons, a.k.a. valence shell electrons
46
Q

what are the trends in atomic radius

A
  • decreases across a period because the core charge increases and pulls each valence electron closer to the nucleus.
  • increases down a group because the effect of the core charge is reduced by the presence of more inner shell electrons which repel each valence electron.
47
Q

what is ionisation energy

A

the amount of energy required to dislodge an electron from an energy shell of a gaseous atom

48
Q

what are the trends in ionisation energy

A

ionisation increases across a period and decreases down a group. this is because the core charge increases from left to right across a period,
but its effectiveness is reduced going down a group.

49
Q

what are the trends in electronegativity

A

as you go across a period electronegativity increases, and it decreases down a group

50
Q

what is electronegativity

A

Electronegativity refers to the ability of an atom to attract an electron into its valence
shell (measured on Pauling scale between 0 and 4.0)

51
Q

what are the trends with reactivity with water

A

For a metal, the chemical reactivity increases as ionisation energy decreases because metals lose electrons when they form a chemical bond.

For a non-metal, the chemical reactivity increases as electronegativity increases because non-metals gain electrons when they form a chemical bond.

52
Q

what is an ionic bond

A

An ionic bond is the electrostatic force of attraction between a positive ion (cation) and a negative ion (anion).

53
Q

what is a covalent bond

A

sharing of electrons between two atoms

54
Q

how do Pauling scale numbers determine the type of bond

A
  • similar electronegativity means they share electrons equally (non-polar covalent bond)
  • difference in electronegativity of 1.0 to 1.7 means they share electrons unequally (non-polar covalent bond
  • difference >1.7 means one atom takes the electrons (ionic bond)
55
Q

what is valency

A

Valency is a number that measures the combining power of an element.

  • For an element forming an ionic compound, the valency refers to the number of charges it possesses when it becomes an ion
  • For an element forming a covalent compound, the valency is the number of covalent bonds it forms
56
Q

what is VESPR

A

Valence Shell Electron Pair Repulsion is used to determine the shape of small molecules

1.The electrons in the valence shell of an atom, including electrons shared from other atoms, will exist in pairs.

2.These electron pairs will get as far away from each other as possible in three dimensions.

  • This is limited when there are double bonds or triple bonds
57
Q

what are polar and non-polar molecules

A

A molecule with non-polar covalent bonds will be a non-polar molecule, i.e. neutral overall with an even distribution of charges.

A polar molecule is neutral overall but has an uneven distribution of charges.

A polar molecule can also be referred to as a dipole

58
Q

what are the types of intermolecular forces

A
  1. dispersion forces
  2. dipole-dipole forces
  3. hydrogen bonding
59
Q

what are dispersion forces

A
  • random movement of electrons can give rise to a temporary dipole
  • this can induce a temporary dipole in adjacent molecules
  • electrostatic forces of attraction arise between the negative and positive poles
  • Dispersion forces are very weak
  • However, they increase as the size of atoms increase (more electrons that randomly move) or if the molecule is linear (more likely to have a polar end)
  • Dispersion forces are always present between molecules
60
Q

what are dipole-dipole forces

A
  • Electrostatic forces of attraction occur between the negative and positive poles of adjacent polar molecules.
  • These are weak forces (1/100th the strength of covalent bond).
61
Q

what is the difference between dispersion forces and dipole dipole forces

A

dipole dipole forces are stronger than dispersion forces. dispersion forces are the force of attraction between non-polar molecules whilst dipole dipole forces are between polar molecules

62
Q

what is hydrogen bonding

A
  • If H bonds with any of the three most electronegative elements (N, O or F), it forms a very polar covalent
    bond.
  • This H atom will be strongly attracted to the lone pair of electrons on N, O or F on an adjacent molecule; this is known as a hydrogen bond.
  • This force is strong (about 1/10th the strength of a covalent bond) because the H atom has a small radius and can allow a neighbouring molecule’s negative pole to approach closely.
63
Q

what are the effects of intermolecular forces

A
  • melting and boiling point
  • surface tension
  • solubility
64
Q

what is the effect of intermolecular forces on melting and boiling point

A
  • The stronger the intermolecular forces, the higher the melting point and boiling point.
  • More energy is required to move particles away from each other when changing state.
65
Q

what is the effect of intermolecular forces on surface tension

A
  • Very strong intermolecular forces will increase surface tension in the liquid state.
    -Surface tension refers to the tendency of a liquid to minimise its surface area,
  • This means molecules pull together at the surface of a liquid.
66
Q

what is the effect of intermolecular forces on solubility

A
  • The type of intermolecular force that is present will determine the solubility of a substance in a solvent:

“like dissolves in like”

  • Ionic compounds are able to dissolve in a solvent made of polar molecules, but not always.
67
Q

draw a linear molecule. what are examples of linear molecules

A

CO2, BeH2

68
Q

draw a bent molecule. what are examples of bent molecules

A

H2O

69
Q

draw a trigonal planar molecule. what are examples of trigonal planar molecules

A

BF3

70
Q

draw a tetrahedral molecule. what are examples of tetrahedral molecules.

A

NH4-

71
Q

draw a trigonal pyramid molecule. what are examples of trigonal pyramid molecules

A

NH3

chemistry year 11 (1 decks)

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