atomic structure (seneca) Flashcards
- Elements & compounds - Chemical reactions & equations - mixtures - model of an atom - atom size & number - atomic number - calculations - isotopes - isotopes- calculations - periodic table - noble gases &halogens - alkali metals - transition metals -
1
Q
what is a Solvent
A
The liquid in which a solid dissolves.
2
Q
what is a solute
A
dissolved solid
3
Q
what is a solution
A
A liquid that contains a dissolved solid.
4
Q
Which technique separates solutions with more than one type of dissolved solid (solute)?
A
chromtography
5
Q
simple distillation separates …
A
2 liquids with different boiling points
6
Q
Simple distillation can also separate a
A
solute from a solvent, when the solvent has a lower boiling point than the solute.
7
Q
Fractional distillation separates
A
lots of liquids with different boiling point
8
Q
what are the steps of fractional distillation
A
The mixture is slowly heated until the liquid with the lowest boiling point boils and then condenses.
Then we increase temperature slowly to collect (boil then condense) the other fractions.
9
Q
what are the steps of simple distillation
A
The mixture is heated until the liquid with the lower boiling point starts to boil.
The vapour released passes through a condenser, where the gas cools back into a liquid.
10
Q
name the main methods of separating liquids
A
Crystallisation
filtration
chromatography
simple distillation
fractional distillation
11
Q
In ,_____ an English physicist called J. J. Thomson discovered electrons.
A
1897
12
Q
In ,1897 an English physicist called ———- discovered electrons.
A
J. J. Thomson
13
Q
In ,1897 an English physicist called J. J. Thomson discovered ——-
A
electrons.
14
Q
what is thomson’s plum pudding model
A
a ball of positive charge (dough), with negatively charged electrons (currants in pudding) mixed in with the ‘dough’.
15
Q
In —–, Ernest Rutherford discovered that alpha particles could bounce back off atoms.
A
1909
16
Q
In 1909, ——— discovered that alpha particles could bounce back off atoms.
A
Ernest Rutherford
17
Q
In 1909, Ernest Rutherford discovered that ———
A
alpha particles could bounce back off atoms.
18
Q
In —–, James Chadwick discovered that some particles in the nucleus have no charge at all. He called them neutrons.
A
1932
19
Q
In 1932, —— discovered that some particles in the nucleus have no charge at all. He called them neutrons.
A
James Chadwick
20
Q
In 1932, James Chadwick discovered that …
A
some particles in the nucleus have no charge at all. He called them neutrons.
21
Q
The radius of atoms is
A
aproximately 0.1 nanometres, or 1x10-10 m.
22
Q
Relative mass =
A
number of protons + number of neutrons
23
Q
In what environment would the relative mass of an atom change?
A
mass is constant across all environments
24
Q
The radius of the nucleus is about ——- smaller than the radius of the atom
A
10,000 times
25
The atomic number is the number -----
of protons in the atom
26
The mass number of an atom (or relative mass) is calculated by ...
adding the number of protons and neutrons found in a nucleus.
27
the mass number of an atom is also called
relative mass
28
Protium is a hydrogen atom with
1 proton and 0 neutrons.
29
99.98% of hydrogen atoms are
protium.
30
Protium is used in
hydrogen fuel cells and the production of plastics.
31
Deuterium is a hydrogen atom with
1 proton and 1 neutron.
32
Around 0.02% of hydrogen atoms are
deuterium.
33
deuterium is used in
nuclear fusion.
34
Tritium is a hydrogen atom with
1 proton and 2 neutrons.
35
Tritium is used in
thermonuclear fusion weapons.
36
Tritium is (%) ...
very rare.
37
what are isotopes
Atoms of the same element that have different numbers of neutrons.
38
The Σ means
sum of
39
calculate relative atomic masses (Ar) with isotope abundance
Σ(isotope abundance x isotope mass number/Σ isotope abundance
40
Σ(isotope abundance x isotope mass number/Σ isotope abundance
The numerator is
'the sum of the isotope abundance times the isotope mass number'.
41
Σ(isotope abundance x isotope mass number/Σ isotope abundance
The denominator is
'the sum of all the isotope abundances'.
42
Electrons fill an atom's shells in order of
increasing energy
43
The closer a shell is to the nucleus,
the lower its energy level, so the first shell that is filled is the closest to the nucleus
44
Electron configuration tells us how
an atom's electrons are organised.
45
in the calculation Σ(isotope abundance x isotope mass number/Σ isotope abundance, Σ isotope abundance will add to ...
100 %
45
relative atomic mass= Σ
(isotope abundance×isotope mass number)/100
46
what is Relative atomic mass (1)
The relative atomic masses (Ar) of elements are calculated using the average mass of all of the isotopes of an element.
47
the horizontal rows of the periodic table are called
periods.
48
Elements in the same column have the -------- in their outer shell (the highest energy level).
same number of electrons
49
Because all elements in a column have the same number of electrons in their outer shell,
they have similar chemical properties.
This means they will all react in similar ways.
50
--------- was the first chemist to devise a periodic table.
John Newlands
51
Newlands' periodic table was ordered by ...
the mass of the element.
52
the Newlands' table was incomplete, and some elements were
placed in inappropriate groups.
53
Dmitri Mendeleev recognised that there may be
undiscovered elements
54
------ added gaps to Newlands’ table to account for undiscovered elements.
Mendeleev
55
Mendeleev even predicted the
properties and masses of these undiscovered elements
56
The discovery of protons and isotopes has shown that Mendeleev ordered elements exactly by
relative atomic mass.
57
Metals have ---- melting and boiling points.
high
58
When metals react, they
lose 1 or more of these negatively charged electrons to form positively charged ions
59
Metals are ---- conductors of heat and electricity.
good
60
Metals are ------------------- at room temperature.
all solids (except for mercury)
61
When non-metals react, they either:
Gain electrons to form negatively charged ions.
Or share electrons to form neutral molecules
62
Non-metals are found on the right of the periodic table because they
have many electrons in their outer shell.
63
non-metals have ---- melting and boiling points than metals
lower
64
Non-metals are often found as
gases.
65
Non-metals generally ----- heat or electricity.
do NOT conduct
66
The elements in Group 0 are
unreactive because they have a full outer electron shell. They do NOT gain or lose electrons to fill up this shell as it is already full.
67
Noble gases can be used in light bulbs because
they will NOT react with the hot metal filament.
68
Because noble gases are unreactive, they exist as
single atoms (monatomic) instead of forming molecules.
69
The noble gases have --- boiling points.
low
70
the noble gases' boiling points do .....
This is because...
- increase as you move down the periodic table.
- the relative atomic mass increases lower down the periodic table.
71
The noble gases (in group 0) have ---- densities
low
72
the noble gases' densities do
this is because ...
This --- density makes them useful....
- increase as you move down the periodic table because of their increasing relative atomic mass.
- This low density makes them useful in balloons.
73
nobles gases are (meaning unreactive)...
inert
74
what are properties of noble gases(5)
inert
colourless
monatomic
low boiling points
low density
75
Halogens are in group -- and so have ...
7
7 electrons in their outer shell.
76
In their elemental form, halogens share electrons to make
diatomic molecules (molecules made of pairs of atoms)
77
When a metal atom transfers its outer electron to a non-metal atom (like a group 7 atom),--------- are formed.
salts
78
As you move down the group, the halogens decrease in reactivity. This is because:
The atoms gain more electron shells.
So, the distance between the outer electron shell and the nucleus increases.
So, the attraction between the nucleus and the electron (to be gained from another element) decreases.
79
As you move down the group, the halogens ------ in reactivity
decrease
80
give two examples of halogens that fluorine displace from a compound?
chlorine and bromine
81
Why do halogens become less reactive as you go down the group?
the electron gained from another element is further from the nucleus
82
Lithium is the ------ reactive of the alkali metals
least
83
Lithium burns with a ------- flame when it reacts with oxygen.
crimson
84
Lithium ----- on the surface of water and will release -------
floats
bubbles of hydrogen gas (it effervesces).
85
Sodium is ----- reactive than lithium because -----
This is because it is
more
its outer electron is less strongly attracted to the positively charged nucleus.
a greater distance from the positive charge of the atom's nucleus.
86
The metal ---- on the surface of water, which releases ---.
The sodium moves
- floats
- enough heat to melt the sodium
- quickly across the surface of the water.
87
Sodium burns with a ------
flame when it reacts with oxygen.
yellow/orange
88
Potassium is more reactive than -----because -----.
lithium and sodium
its outer electron is least strongly attracted to the nucleus
89
The potassium floats on the surface of water, and
has a similar, but more vigorous, reaction compared with sodium
90
Potassium burns with a ---- flame when it reacts with oxygen.
lilac
91
the elements found in group 1 are called
alkali metals
92
when alkali metals react with oxygen, they...
Rapidly turns from silvery shiny to dull as a metal oxide (e.g. potassium oxide) is produced.
93
when alkali metals react with chloride, a...
A metal chloride is formed (e.g. sodium chloride), which dissolves in water to give a colourless solution.
94
when alkali metals react with water they...
The metal floats on the surface and melts to create a metal hydroxide (e.g. lithium hydroxide).
When they react with water, the energy released is enough to melt the metal.
95
As you move down Group 1 of the periodic table, the reactions of alkali metals become
quicker and more vigorous
96
As you move down Group 1 of the periodic table, the reactions of alkali metals become quicker and more vigorous. Explain
The number of electron shells increases meaning there is a greater distance between the outer electron and the nucleus.
The greater the distance between the outer electron and the nucleus, the weaker the attraction between them.
The weaker the attraction between the outer electron and the nucleus, the easier it is for the outer electron to be lost.
97
The transition metals are found in the ------- of the periodic table.
middle
98
Transition metals are -----reactive than alkali metals.
E.g.
less
Iron takes weeks to rust when in contact with oxygen and water, whereas sodium does this in a few seconds.
99
Transition metals have ---- melting points than alkali metals.
E.g.
higher
Iron's melting point is 1,583°C, whereas sodium’s is about 98°C.
100
---- melting points make transition metals useful for ...
High
cooking equipment.
101
Transition metals are ------------ than alkali metals.
stronger and harder
102
Transition metals have more mass for the ---- volume than alkali metals.
The ---- density makes transition metals useful in ----
same
high
construction.
103
form the iron ions with different positive charges
Fe2+, Fe3+
104
form the copper ions with different positive charges
Cu+, Cu2+
105
Copper(I) sulfate is (colour)
white
106
copper(II) sulfate is (colour)
blue.
107
Iron (Fe) is the catalyst used in the ----, which results in the production of ----
- Haber process
- ammonia.
108
Platinum (Pt) and rhodium (Rh) are used as the catalyst for
catalytic converters in cars.
109
Used in catalytic converters in cars.
Platinum
and rhodium
110
Relative to the alkali metals, transition metals have: 1. melting points,2. density and 3. reactivity.
1. higher
2. higher
3. lower
111
Transition metals have special properties of (3)
- are often used as catalysts
- can form colourful compounds
- can form positive ions with different positive charges
112
Which group of elements form DIATOMIC MOLECULES and become LESS REACTIVE as you move down the group?
group 7
113
what are properties of metals?
high melting and boiling points
good conductors
they lose electrons when they react
114
What is the relative atomic mass?
The relative atomic mass is the average mass of an element, weighted according to the abundance of its isotopes, on a scale where carbon-12 has a mass of 12.
115
Why is only half the water evaporated initially in crystallisation for hydrated copper sulfate crystals?
The aim of the experiment is to gain hydrated copper sulfate crystals. This means that the crystal itself should have some water in it.
If the solution is boiled dry, even the copper sulfate will lose its water and become dry, i.e. anhydrous copper sulfate.
Anhydrous copper sulfate is a white solid while hydrated copper sulfate is blue.
If a question asks for a hydrated salt, make sure to mention that you do not boil off all the water. Instead, let half the solution evaporate by itself.
116
what is a ion?
a charged atom either negative or positive
117
What was the name of the atomic model devised by J.J. Thomson?
plum pudding model
118
Rutherford's atomic model was called the -----.
nuclear model
119
What conclusions did Ernest Rutherford draw from his discovery that alpha particles could bounce back off atoms?
an atoms mass is concentrated in its centre
the nucleus contains positively charged particles
120
Calcium carbonate reacts with hydrochloric acid to form calcium chloride, carbon dioxide, and water. what is the balanced equation for this reaction?
CaCO3+2HCI --> CaCl2+CO2+H20
121
Lime water before reacting with carbon dioxide is …
Colourless (NOT CLEAR)
122
Acid + oxides ->
Salt + water
123
Acid + hydroxides ->
Salt + water
124
Acid + carbonates ->
Salt + water + carbon dioxide
125
what are monatomic atoms?
A molecule composed of just one atom, and lacking any covalent bonds
126
Atomic number=
Number of protons
127
What are properties of metals (5)?
- Shiny
- Mostly solid
- Dense and strong
- Malleable
- Good heat and
electrical conductors
128
What are properties of non-metals (5)?
- Dull
- Low density
- Weak
- Brittle
- Poor heat and
electrical conductors
129
What does sonorous mean?
Makes a ringing sound when hit.
