TOPIC 1 - Atomic Structure and the Periodic Table✅ Flashcards
1
Q
What is the radius of Atoms?
A
0.1 Nanometers.
2
Q
Where is the Nucleus in an Atom?
A
In the middle.
3
Q
What does the Nucleus contain?
A
Protons and Neutrons.
4
Q
What is the radius of the Nucleus?
A
1 x 10 to the power -14 m.
5
Q
What charge does the Nucleus have?
A
Positive charge.
6
Q
Almost the whole mass of the atom is….
A
The nucleus.
7
Q
Give 3 facts about Electrons:
A
- They move around the nucleus in electron shells.- Negatively charged.- Have almost no mass.
8
Q
Give the RELATIVE MASS and RELATIVE CHARGE of Proton:
A
1+1 (positive)
9
Q
Give the RELATIVE MASS and RELATIVE CHARGE of Neutron:
A
1 0 (neutral)
10
Q
Give the RELATIVE MASS and RELATIVE CHARGE of Electron:
A
Very small-1 (negatively charged)
11
Q
What does the atomic number tell you?
A
The number of protons and electrons.
12
Q
What does the mass number tell you?
A
The number of protons and the number of neutrons.
13
Q
How to find the number of neutrons:
A
MASS NUMBER - ATOMIC NUMBER.
14
Q
Where is the atomic number?
A
At the bottom.
15
Q
Where is the mass number?
A
At the top.
16
Q
What is the charge in an atom?
A
NEUTRAL. NO CHARGE OVERALL.
17
Q
Why are atoms neutral?
A
Because they have the same number of protons as electrons.
18
Q
What is an ION?
A
An atom or group of atoms that have lost or gained electrons.
19
Q
IN A POSITIVE ION. How do you find the number of electrons?
A
ATOMIC NUMBER - CHARGE.
20
Q
IN A NEGATIVE ION. How do you find the number of electrons?
A
ATOMIC NUMBER + CHARGE.
21
Q
In an ion, the number of protons doesn’t equal the number of electrons. What does this mean?
A
It has an overall charge.
22
Q
What does it mean if an ION has a 2- charge?
A
It has 2 more electrons than protons.
23
Q
What is an element?
A
A substance made up of atoms that all have the same number of protons in their nucleus.
24
Q
Elements are made up of….
A
Atoms with the same Atomic Number.
25
The smallest part of an element that you can have is....
A single atom of that element.
26
The number of protons in the nucleus decides...
What type of atom it is.
27
An atom with one proton is...
Hygrogen.
28
If a substance only contains atoms with the same number of protons it's called....
An element.
29
Atoms can be represented by Symbols. Give the symbol for Magnesium.
MG.
30
What are Isotopes?
Atoms with the same number of protons but a different number of neutrons.
31
Isotopes have the same atomic number but....
different mass numbers.
32
If an element has a different number of isotopes, how can you describe it?
Using relative atomic mass ( A r) instead of mass number - this is an avergae mass.
33
FORMULAE TO WORK OUT RELATIVE ATOMIC MASS:
SUM OF (Isotope abundance (amount) x Isotope mass number) DIVIDED BY sum of abundances of all the isotopes.
34
When two or more elements react, what do they form?
Compounds.
35
What are compounds?
Substances that contain atoms of different elements.
36
What are atoms held together by in a compound?
Chemical bonds.
37
What is the only way to seperate elements in a compound?
By using a chemical reaction.
38
What does a formula show?
What atoms are in a compound.
39
What do word equations show?
The names of the chemicals that are reacting and being produced.
40
Give 2 points about MIXTURES:
- Mixtures contain at least two different elements or compounds.- There aren't any chemical bonds between the different parts of the mixture.
41
Air is a mixture of gases, mainly....
nitrogen, oxygen, carbdon dioxide and argon.
42
Give the 5 physical methods that can seperate different parts of a mixture:
- Filtration.- Crystalisation.- Simple Distillation.- Fractional Distillation.- Chromatography.
43
What can Chromatography be used for?
It can be used to separate different dyes in an ink.
44
List the 8 steps to CHROMATOGRAPHY:
1) Draw a line near the bottom of a sheet of filter paper in pencil so it won't dissolve.2) Add a spot of ink to the line.3) Add a small amount of solvent into the beaker so it forms a shallow layer.4) Place the sheet in the beaker and make sure the ink isn't touching it so it won't dissolve.5) Place a kid on top of the container to stop the solvent from evaporating.6) When the solvent has nearly reached the top of the paper, take the paper out of the beaker to dry.7) Each ink moves up the paper at different speeds which separates it. There should be one spot for each dye in the ink.
45
What is the pattern of spots that happens as a result of Chromatography called?
Chromatogram.
46
What does FILTRATION separate?
Insoluble solids from liquids.
47
Give the 4 steps to FILTRATION:
1) Put some filter paper on a funnel.2) Pour the mixture into the filter paper.3) Make sure the mixture doesn't go above the filter paper.4) The liquid passes through the paper into the beaker and the solid is left behind in the filter paper.
48
Give the two ways to separate soluble solids from solutions (a dissolved solid).
- Evaporation.- Crystallisation.
49
Give the 3 steps to Evaporation:
1) Slowly heat the solution in an evaporating dish - the solvent will evaporate.2) Eventually, crystals will form.3) Keep heating until you are left with dry crystals.
50
Why would you use crystallisation instead of evaporation?
You can only use evaporation if the salt doesn't break down when it's heated. If it does, you use crystallisation.
51
Give the 4 steps to crystallisation:
1) Gently heat the solution in an evaporation dish and some of the solvent will evaporate.2) once some of it has evaporated or when you see crystals start to form, stop heating and leave the solution to cool.3) The shalt should start to form crystals.4) Filter the crystals out of the solution and leave them in a warm place to dry.
52
Rock salt is a mixture of...
Salt and sand.
53
What 2 methods can you use to separate rock salt?
Filtration and Crystallisation.
54
Give the 4 steps to separating rock salt using filtration and crystallisation:
1) Grind the mixture to make sure the salt crystals are small so will dissolve easily.2) Put the mixture in water and stir - the salt will dissolve but the sand won't.3) Filter the mixture, the grains of sand won't fit through the filter paper but the salt will pass.4) Use evaporation or crystallisation so that you end up with dry crystals of the salt.
55
What is SIMPLE DISTILLATION used for?
Separating a liquid from a solution.
56
Give the 5 steps to SIMPLE DISTILLATION:
1) First, the solution is heated.2) The part of the solution that had the lowest boiling point evaporates first and turns into a gas.3) The gas travels into the condenser.4) in the condenser, the gas is cooled and condensed - turned back into a liquid.5) The liquid drops out of the condenser and can be collected while the rest of He solution is left behind in the flask.
57
Why can't you always use simple distillation? What can you use instead?
Can't be used to separate mixtures of liquids with similar boiling points so you need to use something like FRACTIONAL DISTILLATION.
58
Give the 8 steps to FRACTIONAL DISTILLATION: complete
1) Put your mixture in a flask and stick a fractionating column on top then heat it.2) The different liquids have different boiling points so they will evaporate at different temperatures.3) When the temperature on the thermometer matches the boiling point of this substance, it will reach the top of the column.4) The substance will then enter the condenser where it cools and condenses.5) You can collect the liquid as it drips out of the condenser.6) When the first liquid has been collected, raise the temperature until the next one reaches the top.
59
What is FRACTIONAL DISTILLATION used for?
To separate a MIXTURE of liquids that have similar boiling points.
60
What did scientists think the atom was?
A solid sphere.
61
What did scientists actually find out about atoms?
That atoms contain even smaller, negatively charged particles called ELECTRONS.
62
What did the discovery of electrons lead to?
The PLUM PUDDING MODEL.
63
What does the Plum Pudding Model show?
The atom as a ball of POSITIVE CHARGE with electrons scattered in this ball.
64
What experiment did scientists carry out to show that the Plum Pudding was wrong?
Alpha particle scattering experiments.
65
What is the Alpha Particle Scattering experiment?
Firing positively charged alpha particles at a very thin sheet of gold.
66
What did scientists expect when the alpha particles were shot through the very thin sheet of gold? (2)
-Some thought they would go straight through the sheet.-Some thought a few particles would change direction by a small amount.
67
Why were scientists suspicions wrong about the alpha particles?
Their thoughts were wrong because a small number of particles went BACKWARDS.
68
Since the PLUM PUDDING MODEL turned out to be wrong, what did scientists come up with instead?
The nuclear model of the atom.
69
What was the idea of the Nuclear Model? (4)
1) There's a ring positively charged nucleus at the centre of the atom.2) Most of the mass is in the nucleus.3) The nucleus is surrounded by a cloud of negative electrons.4) Most of the atom is empty space.
70
How did Niels Bohr change the nuclear model of the atom?
He suggested that electrons orbit the nucleus in shells which are at a fixed distance from the nucleus.
71
In the early 1800's, how were elements arranged on the periodic table?
Scientists had no idea of an atomic number so they used relative atomic mass to arrange them.
72
Why were the early periodic tables not complete?
Because not all of the elements had been found yet and putting the elements in order of atomic mass meant that some elements were also put in the wrong column.
73
What did Dmitri Mendeleev do to the periodic table in 1869?
He arranged them into a table and ordered them mainly by atomic mass and left gaps for elements that hadn't been found yet.
74
How do Isotopes prove that Mendeleev was right?
Isotopes have different atomic masses but share the same properties so they have the same position on the periodic table so Mendeleev was right to swap some elements to keep properties together.
75
What did experiments by James Chadwick show?
That the nucleus also contained neutral particles - neutrons.
76
Give the 5 rules for the electron shell:
1) Electrons always move in shells.2) The inner shells are always filled up first.3) Only a certain number of electrons are allowed in each shell - 2,8,8.4) Atoms are a lot more stable when they have full electron shells.5) In most atoms, the outer shell is not full so atoms will react to fill it.
77
Approximately, how much elements are there?
100.
78
In the periodic table, how are elements ordered?
In order of the increasing atomic number.
79
Where are metals found on the periodic table?
To the left.
80
Where are non metals found on the periodic table?
To the right.
81
How are elements with similar properties arranged?
In columns which are groups.
82
The group number of an elements is the same as...
The number of outer shell electrons it has except for Group 0.
83
Most elements are...
Metals.
84
What are metals?
Elements which can form positive ions when they react.
85
What kind of ions do non metals form when they react?
Positive ions.
86
Atoms are more stable with a full outer shell. What does this mean?
They react by losing, gaining or sharing electrons.
87
Metal elements are to the left and bottom of the periodic table so they...
Lose electrons quite easily. When this happens, they form positive ions, with a full outer shell.
88
Non metals are to the right of the periodic table and towards the top. What does this mean?
It's easier for them to share or gain electrons to get a full outer shell.
89
List 3 properties of metals:
1) They're strong but can be bent (malleable).2) They can conduct heat and electricity.3) They have high boiling and melting points.
90
List 5 properties of non metals:
1) They tend to be dull looking.2) they are more brittle so they can break easily.3) They're not always solids at room temperature.4) They don't usually conduct electricity.5) They have a lower density.
91
Group 1 elements are...
Reactive, soft metals.
92
As you go down Group 1, what happens? (2)
- Melting and boiling points get lower.- Relative atomic mass goes up.
93
Why does reactivity increase as you go down group 1 elements?
The outer electron is more easily lost as it gets further from the nucleus because it is less attracted to it.
94
What are group 1 elements known as?
Alkali metals.
95
What do Alkali Metals (Group 1 elements) form with non metals?
Ionic compounds.
96
What is reaction of group 1 elements and water like? (2)
1) The reactions are vigorous and produce a metal hydroxide and hydrogen gas.2) The more reactive an alkali metal, the more violent the reaction.
97
What are Lithium, Sodium and Potassium like when they react with water?
They float and move around the surface, fizzing furiously.
98
What is Potassium like when it reacts with water?
The reaction gives out enough energy to ignite hydrogen (set it on fire.)
99
What are Group 2 metals like when they react with chlorine? (2)
1) Group 1 metals react vigorously when heated in chlorine gas to form where salts called metal chlorides.2) As you go down the group, the reaction gets more vigorous.
100
What are Group 1 elements like when they react with oxygen? (3)
1) They form metal oxide.2) Different types of oxide will form depending on the Group 1 element.3) They are usually shiny but when they react with oxygen, they tarnish.
101
Why do Group 1 elements tarnish when they react with oxygen?
Because a layer of metal oxide is formed on the surface.
102
Give the word equation for when Group 1 elements react with water:
Alkali metal + water ---> Metal Hydroxide + Hydrogen.
103
Give the word equation for when Group 1 elements react with chlorine:
Alkali metal + Chlorine ----> Metal Chloride.
104
What are group 7 elements known as?
The halogens.
105
The halogens form molecules that contain...
2 atoms.
106
What are the elements in Group 7 like as you go down? (3)
1) Less reactive as its harder to gain an extra electron as the outer shell is further from the nucleus.2) Higher melting and boiling points.3) Higher relative atomic masses.
107
Why do Group 7 elements react in similar ways?
Because they all have 7 electrons in their outer shell.
108
What happens when Group 7 elements react with other non metals?
They share electrons and form covalent bonds so they can get a full outer shell.
109
Halogens form...
Molecular compounds.
110
What do Halogens form with metals?
Ionic bonds.
111
What happens in a displacement reaction? (using halogens as an example).
The more reactive halogen changes from a halogen into a halide ion which becomes part of the salt.
112
What are Group 0 elements known as?
The noble gases.
113
What are Group 0 elements like at room temperature?
Colourless gases.
114
How does the full outer shell in noble gases affect them?
They have a stable outer shell so they are unreactive and don't form molecules easily so the elements are single atoms.
115
What happens to the relative atomic masses of the elements as you go down the noble gases?
It increases so they have more electrons which means stronger forces between atoms.
116
As you go down Group 0, what happens to the boiling points?
It increases because there are stronger forces.
