atomic structure and the periodic table Flashcards
(121 cards)
1
Q
what is the basic structure of an atom?
A
- nucleus - made up of protons and neutrons
- electrons orbiting the nucleus in rings in shells
2
Q
what charge do protons have?
A
positive: +1
3
Q
what charge do neutrons have?
A
neutral: 0
4
Q
what charge do electrons have?
A
negative: -1
5
Q
what is the atomic mass of protons neutrons and electrons?
A
protons: 1
Neutrons: 1
electrons: 0 or very small
6
Q
what do we call an atom that has a positive or negative charge?
A
an ion
7
Q
what is the mass number?
A
the number of protons and neutrons in an atom
8
Q
what is the atomic number?
A
the number of protons in an atom
9
Q
on the periodic table is the mass number at the top or the bottom
A
at the top
which means the atomic number is at the bottom
10
Q
how can we find the number of neutrons
A
by taking away the atomic number from the mass number
11
Q
what is roughly the radius of an atom
A
0.1 nanometres
12
Q
If an atom has 6 protons and 5 electrons, what charge will it have overall?
A
+1
13
Q
Which particle determines what element an atom is?
A
protons
14
Q
what is an isotope ?
A
an isotope is different forms of the same element with the same number of protons but a different number of neutrons
15
Q
what is the symbol for relative atomic mass
A
AR
16
Q
An atom has 13 protons and 14 neutrons. What is its mass number?
A
27
17
Q
Four atoms have the numbers of protons and neutrons given below. Which two atoms are isotopes of the same element?
Atom W: 11 protons and 10 neutron
Atom X: 10 protons and 10 neutrons
Atom Y: 9 protons and 9 neutrons
Atom Z: 10 protons and 9 neutrons
A
atom Z and X
18
Q
Lithium naturally exists as two isotopes: lithium 6, with an abundance of 7.6%, and lithium 7, with an abundance of 92.4%.
What is the relative atomic mass of lithium?
A
= 6.92
sum of = (isotope abundance x isotope mass)
sum of = abundance of all isotopes
19
Q
what is a molecule
A
2 or more atoms that are chemically bonded
20
Q
what is a compound
A
2 or more different elements that are held together by chemical bonds
21
Q
what is a mixture
A
2 or more elements that are not chemically combined
22
Q
Is carbon dioxide (CO2) a molecule, a compound, or both?
A
both
it is a molecule because it has two or more atoms chemically bonded and it also has 2 or more different elements held together by chemical bonds
23
Q
Is the air all around us a compound or a mixture?
A
a mixture
mainly oxygen,nitrogen,carbon dioxide
24
Q
Is seawater a compound or a mixture?
A
a mixture
sea water has different substances for example H2O and NaCl but these substances are NOT chemically combined so it is not a compound
25
give an example of a molecule
- O2
- N2
- CO2
26
give examples of a compound
- H2O
- CO2
27
Balance the following chemical equation:
N2 + H2 ➔ NH3
N2 + 3H2 ➔ 2NH3
28
Balance the following chemical equation:
CH4 + O2 ➔ CO2 + H2O
Balance the following chemical equation:
CH4 + 2O2 ➔ CO2 + 2H2O
29
When representing oxygen in a symbol equation, should you write 'O' or 'O2'?
O2
30
Choose the correct balanced equation for the reaction of iron and chlorine:
Fe + Cl3 ➔ FeCl3
2Fe + 3Cl2 ➔ 2FeCl3
2Fe + Cl2 ➔ 2FeCl3
2Fe + 3Cl2 ➔ 2FeCl3
31
what does soluble and insoluble mean
soluble means capable of dissolving in a liquid
insoluble means incapable of dissolving in a liquid.
32
what is a solvent?
A solvent is a liquid in which substances can dissolve.
e.g water
33
What is the best method to obtain a sample of salt from a salt solution?
evaporation
34
Describe how you would carry out the process of crystallisation.
First, pour the solution into an evaporating dish and heat it using a Bunsen burner.
Stop heating it when crystals start to form and allow it to cool down.
Then either leave it to allow the rest of the water to evaporate, or filter out the crystals using filter paper and a funnel. Lastly, dry the crystals in a warm oven.
35
Describe how you would carry out the process of evaporation
put the solution into a evaporation dish
slowly heat the solution
the solvent will start evaporating and the solution will get more concentrated
eventually crystals will start to form
keep heating until only dry crystals remain.
36
what are the benefits and disadvantages of evaporation?
- evaporation is easy and quick
- some solids can decompose because of the heat.
37
Describe how you would carry out the process of filtration
put filter paper in a funnel and place the funnel in a beaker.
pour the solution into the paper and leave it until all of the solvent has been filtered through on only the solid is left behind.
38
what does the water jacket do?
| simple distillation practical
cold water is continously running through the water jacket so when the vapour goes through the condenser it condenses into a liquid.
39
what happens in simple distilation
| simple distillation practical
you heat the solution and it evaporates.
as it moves up the flask the pressure will push it back down and into the condenser.
the water jacket surrounding the condenser will cool the vapour and condense into a liquid because of the cold water that runs continuously though it.
the liquid will run down the condenser and collect in a beaker.
the solid that has been separated from the solution will remain in the flask.
40
what is the point of a bung?
to make sure no gas escapes.
41
explain the process of fractional distillation to separate a mixture of the liquids methanol, ethanol and propanol.
first you heat the flask with the mixtures in it to the lowest boiling point of the 3 substances.
the substance will evaporate into the fractional collum and be pushed into the condenser and will condense into a liquid by the water jacket and will collect in the beaker. the other substances may also evaporate but the tiny glass rods in the fractional collum are much cooler than their boiling point so they will condense and fall back into the flask. the temperature of the bunsen will be changed to the boling point of the other substances and the process happens again until the pure liquid for each is collected
42
Fractional distillation can separate a mixture of several liquids that each have different:
Boiling points
Colours
Melting points
boiling point
43
what was the atomic theory and who created it and when?
the atomic theory was the idea that everything was made from tiny little particles that cant be broken down any further.
- they were also separated from each other by empty space
- idea by Democritus 500 BC
- small spheres
44
what was john Dalton idea of the atom?
and when
john Dalton suggested that atoms where solid spheres
- he also suggested that the different types of spheres made up the different elements
- 1800
45
what was jj Thompson theory in 1897
JJ Thompson did a series of experiences that proved that John Dalton idea was wrong and that atoms couldn't be solid spheres.
he also found out that atoms must contain negatively charged particles that we now call electrons.
he came up with the plum pudding model which was a general ball of positive charge with electrons embedded inside it.
46
what was Ernest Rutherford experiment to prove that the plum pudding model was wrong.
rutherford fired positive alpha particles at a thin sheet of gold foil and if they positive charge in the gold atoms were spread out like JJ thompson suggested then the alpha particles should pass through the gold
- instead some deflected in different directions and some reflected back proving is theory wrong
47
what was the alpha particle scattering experiment
In Rutherford's experiments, alpha particles were fired at a thin sheet of gold foil.
Most particles passed through, but some were deflected off course.
This caused him to hypothesise that there was a dense region of positive charge at the centre of the atom that repelled the alpha particles.
As a result he developed the nuclear model of the atom, in which there was a central positive nucleus where most mass was concentrated , surround by negative electrons.
48
what was the nuclear model and who mad it
Rutherford created the nuclear model.
- a compact nucleus with a negative charge surrounding it in a cloud.
49
what was wrong with the nuclear model
there was nothing stopping the cloud of negative charge rushing into the nucleus which would make the atom collapse
50
what did niels Bohr suggest about the atom
he suggested that negativity charged electrons orbit the nucleus in shells.
the orbiting of the electrons prevents the atom from collapsing
51
what did Rutherford suggest for the second time
- Rutherford suggested that the nucleus was made up of small discrete particles know as protons
52
what did James Chadwick suggest
- he provided evidence that the nucleus also contained neutral particles which we know as neutrons
53
what is the order of the history of the atom
- atomic theory - Democritus
- solid spheres - dalton
- plum pudding model - jj
- nuclear model - Rutherford
- niels Bohr - electrons orbiting
- protons - Rutherford
- neutrons - chadwick
54
An atom of magnesium has the electron structure 2, 8, 2.
When a magnesium atom takes part in a reaction, the atom loses _ electrons.
The new electron structure is: _ , _
An atom of magnesium has the electron structure 2, 8, 2.
When a magnesium atom takes part in a reaction, the atom loses 2 electrons.
The new electron structure is: 2, 8.
55
what is the atomic configuration when drawing electrons
2,8,8
56
An atom of oxygen has 6 electrons in the outer shell. In a reaction, it gains 2 electrons.
What is the charge of the oxide ion created?
-2
57
noble gases have completely _____ outer shells
which means......
noble gases have completely full outer shells
which means they dont really react because they dont want to loose or gain a electron
58
The ________ table displays all of the known elements.
A row of elements is called a ______, while each column is called a _____.
The periodic table displays all of the known elements.
A row of elements is called a period, while each column is called a group.
59
True or false? Elements within a period show similar chemical properties to each other.
false
Elements within the same group have similar chemical properties.
60
The atoms of elements in the same group have the same number of:
electrons in their outer shell
61
The alkali metals in group 1 of the periodic table all have how many electrons in their outer shell?
1
62
The atoms of elements in the same period have the same number of
shells
63
When metal atoms react, they _____
electron(s) from their outer shell.
This creates ions with a ______
charge.
loose
positive
64
Fluorine atoms have 7 electrons in their outer shell. In chemical reactions, do they gain or lose electron(s)?
gain
65
what are the general properties of metals?
- metallic bonding
- malleable
- good conductors
- high melting and boiling point
- shiny
- sonorous
66
what are the general properties of non metals?
- dull
- brittle
- low melting and boiling points
- poor conductor
67
why is the periodic table different to how it is now
because scientists had no idea about atomic structure or of protons neutrons and electrons so there was no such thing as a atomic number
68
why did Dmitri leave gaps in his periodic table
to indicate the existence of undiscovered elements
69
what proved Dmitris periodic table was wrong
the discovery of isotopes
70
group 1 elements are...
alkali
reactive
soft
low density
lower melting and boiling points
high relative atomic mass
71
what happens when group 1 elements react with water
react vigorously
produce hydrogen gas and metal hydroxides
72
what happens when group 1 elements react with chlorine
react vigorously when heated with chlorine
forms white metal chloride salts
73
what are the group 7 elements called and what are they
halogens
non metals
coloured vapour
74
what is fluorine
very reactive,very poisonous yellow gas
75
what happens are you go down the group 7
- less reactive
- higher melting and boiling point
- higher relative atomic mass
76
why dont group 0 elements react
full outer shell so no need to gain or loose electrons ( they are inert)
77
what is monotonic gas and which element group are they
a monotonic gas is are single atoms not bonded together
group 0
78
what are the properties of group 0 elements
colourless at room temp
non-flammable
79
why is there a increasing boiling point as you go down the group 0
because there is a increase in the number of electrons in each atom leading to a greater molecular force between them which it has to overcome
80
what does inert mean
generally unreactive
81
Which particle determines what element an atom is?
proton
82
what is a element
a substance that only contains atoms with the same number of protons
83
what is the relative atomic mass
an average mass taking into account the different masses and abundances of all the isotopes that make up the element
84
how can you work out the relative atomic mass
sum of (isotope abundance x isotope mass)
DIVIDED BY
sum of all isotopes
85
what does making compounds involve
giving, taking or sharing electrons because compounds from when elements react and atoms combine
86
what isn't affected when a bond is made ( compounds)
the nuclei of the atom
87
what is the formula of ammonia
NH3
88
what is the formula of carbon monoxide
CO
89
what is the formula of sodium chloride
NaCl
90
what is the formula for Hydrochloride acid
HCL
91
what is the formula of calcium chloride
CaCL2
92
what is the formula of sodium carbonate
Na2CO3
93
what is the formula for sulfuric acid
H2SO4
94
examples of mixtures
crude oil
sea water
the air
95
what is the chromatography practical
- line a the bottom of filter paper (pencil)
- put a spot of ink on the pencil line and place in the solvent
- place paper in solvent
- make sure ink isnt touching solvent
- solvent will seep up paper
- the dye will move up the paper at different rates and seperate out
96
what does it mean if one of the inks stays on the baseline in a chromatogram
a ink in the dye in insouble
97
in the early 1800s what were the two ways elements were categorised
their physical and chemical properties
their atomic weight
98
how was dmitri mendeleevs table of elements organised
mainly in atomic weight
but the order was switched if the properties meant it should be changed
99
when did dmitro create his table of elements
1869
100
what are metals
elements that can from positive ions when they react
101
what is the trend as you go down group 1
they have increasing reactivity
102
what are metal hydroxides
compounds that dissolve in water to produce alkaline solutions
103
what happens when group 1 metals react with oxygen
they form a metal oxide
104
what is chlorine
fairly reactive,poisonous dense green gas
105
what is bromine
a dense,poisonous, red brown volatile liquid
106
what is iodine
a dark grey, crystalline soild or purple vapour
107
what is the trend as you go down the group 7
they become less reactive
have higher boiling and melting points
have higher relative atomic masses
108
what properties are seen in group 7 elements?
They can form covalent bonds with other non-metals
Their ions usually have a 1- charge
109
what is a halide
when a halogen gains a electron to form a -1 ion its called a halide
110
what is a displacement reaction in terms of halogens
when a more reactive halogen replaces the less reactive halogen
111
what happens as you go down group 0
-increasing boiling points
- increasing relative atomic masses
112
why does the boiling point increase as you go down the group 0
there is a increase in electrons in each atom which creates greater intermolecular forces between them which needs to be overcome
113
what is a diatomic molecule and which group exists as them
The halogens exist as diatomic molecules, meaning each molecule consists of two atoms.
114
Explain why the reactivity of group 1 metals increases as you go down the group.
The atomic radius increases down the group (the atoms get larger).
The force of attraction between the nucleus and outer electron decreases.
The electron is lost more easily (requires less energy to remove) from atoms lower down the group.
115
why is there a increase in boiling point as you go down the noble gases
there are more electrons so there are greater intermolecular forces that need to be overcome
116
formula for nitrate ion
N3-
117
formula fro hydroxide ion
OH-
118
formula for sulphate ion
So4 2-
119
formula for carbonate ion
Co3 2-
120
formula for aluminium ion
NH4+
121
Suggest what would happen to the temperature of the water as it flows through the condenser.
the temperature of the water increases
he hot vapours transfer heat to the water, causing the water's temperature to increase as it flows through the condenser.
