Atomic structure and periodic tabler Flashcards
(161 cards)
1
Q
What is an atom?
A
Smallest part of an element that can exist.
2
Q
What do atoms contain?
A
Atoms contain protons, neutrons and electrons.
3
Q
What is the radius of an atom?
A
0.1 nanometres
4
Q
What does the nucleus contain?
A
Protons and neutrons
5
Q
What is the radius of the nucleus?
A
1 x 10 (to power of-14)
6
Q
Is the nucleus positively or negatively charged?
A
Positively charged
7
Q
Why is the nucleus positively charged?
A
Because of its protons.
8
Q
Where is most of the mass of a Atom located?
A
Nucleus
9
Q
What orbits the nucleus?
A
Electrons
10
Q
Why do atoms have a neutral charge?
A
Because they have the same number of protons as electrons.
11
Q
What is the relative mass of a Proton?
A
1
12
Q
What is the relative mass of a Proton?
A
1
13
Q
What is the relative mass of an electron?
A
Very small
14
Q
What is the charge of a proton?
A
+1
15
Q
What is the charge of a Neutron?
A
0
16
Q
What is the charge of an electron?
A
-1
17
Q
What is an Ion?
A
they are atoms with an overall charge . they have gained or lost electrons.
18
Q
Do positive ions gain or lose electrons?
A
lose electrons
19
Q
Do negative ions gain or lose electrons?
A
Gain electrons
20
Q
What is the top the an element called?
A
Mass number
21
Q
What is the bottom of an element called?
A
Atomic number
22
Q
What does the mass number tell you?
A
The total number of protons and neutrons in the atom.
23
Q
What does the atomic number tell you?
A
How many protons there are.
24
Q
What is an element?
A
Is a substance with only one type of atom which has the same atomic number.
25
What are isotopes?
They are different forms of the same element which have the same number of protons but a different number of electrons .
26
Oxygen has a mass number of 16 and an atomic number of 8 with a charge of -2 what is the number of protons, neutrons and electrons?
8 protons
8 Neutrons
10 electrons
27
Aluminum has a mass number of 27 and an atomic number of 13 with a charge of +3 what is the number of protons, neutrons and electrons?
13 protons
14 neutrons
10 electrons
28
What is relative atomic mass?
it is the weighted mean mass of an element, taking into account all of the different isotopes and their relative abundance (amounts)
29
What is the formula to find the relative atomic mass of an element?
Relative atomic mass = Sum of (isotope abundance X isotope mass number/ sum of abundances of all the isotopes( 100)
30
Copper has two stable isotopes. Cu-63 has an abundance of 69.2 and Cu-65 has an abundance of 30.8%. Calculate the relative atomic mass of copper to 1 decimal place?
RAM = (69.2 X 63) + (30.8 + 65)/69.2 + 30.8
= 4359.6 + 2002/100
=6361.6/100 = 63.616
= 63.6
31
What is a compound?
Two or more elements which are chemically joined together in fixed proportions.
32
What is another key fact about compounds?
They usually have totally different properties to the elements that they are made from.
33
If we want to separate a compound back into its elements what do we need to do?
We need to use a chemical reaction to do this.
34
Making bonds involve what?
involves atoms giving away, Taking or sharing electrons. Only the electrons are involved ( the nuclei of the atoms aren't affected at all when a bond is made)
35
What is a Molecule?
It has any elements chemically joined e.g. Ca(OH)2
36
What is a Formula?
It shows what atoms are in a compound in same proportions for example carbon dioxide is formed when 1 carbon atoms reacts with 2 oxygen atoms to give a compound of Carbon dioxide.
37
What is Formula for Carbon dioxide?
Co2
38
What is Formula for Ammonia?
NH3
39
What is Formula for Water ?
H20
40
What is Formula for Sodium Chloride?
NaCl
41
What is Formula for Carbon monoxide?
CO
42
What is Formula for Hydrochloric acid?
HCI
43
What is Formula for Calcium chloride?
CaCl2
44
What is formula for Calcium carbonate?
Na2CO3
45
What is formula for Sulfuric acid?
H(2)S04
46
If a formula e.g Ca (OH)2 has a two outside the bracket what does it mean?
The little number outside the bracket applies to everything in bracket so the formula Ca (OH)2 has 1 calcium atom, 2 oxygen atoms and 2 hydrogen atoms
47
Why are Mixtures easy to separate?
Because they are not like compounds they do not have chemical bonds.
48
What is a Mixture?
It consists of two or more elements or compounds not chemically bonded together, they are not in fixed proportions and the chemical properties are not affected being a mixture. (e.g a mixture of iron powder and sulfur powder will show the properties of both iron and sulfur. it will contain grey magnetic bits of iron and bright yellow bits of sulfur)
49
What is Chromatography?
Separating two or more dissolved solids from a solution.
50
What is the method of paper chromatography?
1) Draw a line near the bottom of a sheet of filter paper
(use a pencil because its insoluble(will not dissolve in solvent)
2)Add a spot of the ink on the line and place the sheet in a beaker of water or solvent.
3) Make sure ink isn't touching the water
4) The solvent seeps up the paper, carrying the ink with it.
4)Watch each different dye in the pink separate out at different rates.
5)When a solvent has nearly reached top of paper take it out the beaker wait for it to dry then the end result is a pattern of spots called chromatogram.
51
What is Filtration?
It separates insoluble(cannot dissolve in water) solids from liquids
52
What is the method of Filtration?
1) Set up apparatus with filter paper sitting in a concial flask
2) Pour insoluble solid and liquid mixture into the concial flask through the cone.
3) The liquid particles are small enough to fit through the filter paper but the solid particles are too big to pass through filter paper, so they are left behind.
4) the solid left behind is called residue and the liquid left behind is called the filtrate.
53
What is Evaporation
Separating soluble solids from solutions
54
What is the method of getting pure dry salt from a solution? (Evaporation)
1) Pour the solution into an evaporating dish.
2) Slowly heat the solution, until crystals start to form as the solvent will evaporate.
3) Keep heating the evaporating dish until all you have left is dry crystals.
55
What is Crystaliation?
Separating soluble solids from solutions
56
What is the method of getting pure dry salt from a solution? (Crystalization)
1) Solution is placed in a evaporating dish and is heated.
2) As solution is heated the water in solution is heated meaning less water.
3) Once water is evaporated crystals will appear, so remove dish from the Bunsen burner and leave it to cool.
57
What is Rock Salt?
It is a mixture of salt and sand. Salt and sand are both compounds but salt dissolves in water and sand doesn't
58
What can filtration and crystallization be used for?
To separate rock salt
59
What is the method used to separate rock salt?
1) Grind mixture to make sure the salt crystals are small
2) Put measure in water and stir
3) Filter the mixture (sand wont fit through the tiny holes in filter paper so solid particles are left behind)
4) Evaporate the water from the salt so that it forms dry crystals.
60
A student needs to produce pure crystals of copper sulfate from an aqueous solution of copper sulfate. Describe how the student could use crystallization for this process.
Pour the copper sulfate solution into an evaporating dish and slowly heat the solution until crystals form or some of the solvent has evaporated. Leave the dish to cool until crystals form. Filter and than dry the crystals using a dry oven
61
What is simple distillation?
Separates the solvent(the liquid that does the dissolving) from a solution.
62
What is the method for simple distillation (of saltwater)?
1) The solution is heated (the solution with the lowest boiling point heats first)
2) Water evaporates and its vapours rise. The water vapour passes into the condenser, where it cools and condenses, liquid water drips into the beaker.
3) All the water has evaporated from the salt solution which is left in the water(pure water), leaving the salt behind.
63
How is simple distillation used in real life?
Purifying salty water to become drinkable
64
What is Fractional distillation used for?
To separate two or more liquids which have different boiling points.
65
What is the method for Fractional distillation?
1) You put your mixture in a flask and stick a fractionating column on top then heat it
2) The liquid with the lowest boiling point will evaporate first. When the temperature on the thermometer matches the boiling point of this liquid, this will rise to the top of the column.
3) Liquids with high boiling points might also start to evaporate, but the column is cooler towards the top. So they will only get part of the way up before they will condense and running back down the flask.
4) When the first liquid has been collected, you raise the temperature until the next one reaches the top.
66
Propan-1-ol, methanol and ethanol have boiling points of 97'C, 65'C and 78'C respectively. A student uses fractional distillation to separate a mixture of these compounds. State which liquid will be collected in the second fraction and explain why.
Ethanol because ethanol has the second lowest boiling point and will be collected once all the methanol has been distilled off and the temperature has increased
67
What did John Dalton describe atoms in the early 19th century?
He described it at solid spheres and different spheres made up the different elements.
68
What did JJ Thompson discover in 1897?
The plum pudding model which showed the atom as a ball of positive charge with electrons stuck to it.
69
How did Ernest Rutherford disprove the Plum pudding model?
He conducted an experiment called the alpha particle scattering experiment, where he fired positively charged alpha particles at a extremely thin sheet of gold. The scientist expected the alpha particles to pass straight through, but some were deflected more than expected and a small number was deflected backwards.
70
What did Ernest Rutherford discover?
The nuclear model of an atom, where there is a tiny positively charged nucleus at the center, where there is most mass and a cloud of negative electrons surrounds it, therefore the atom is mostly made up with empty space.
71
What did Niels Bohr discovered?
Electrons orbit the nucleus in fixed shells and each shell is a fixed distance from the nucleus. Other scientists agreed.
72
What happened several years later the Nucleus Model?
The positive charge in the nucleus is due to tiny positive particles called protons.
73
What did James Chadwick discover 20 years later?
The nucleus also contains neutral particles called neutrons.
74
How were elements classified in the early 1800 s?
1) Their physical and chemical properties
2)In order of atomic mass
This was because at the time there was no idea of Protons, neutrons and electrons.
75
Why is the periodic table called this?
Elements with similar properties, occur at regular intervals
76
What did Dimitiri Mendeleev do with the elements
He arranged them in order of atomic mass
77
What two measures did Mendeleev take in 1869?
1) Sometimes he switched the order of elements so they fitted the patterns of other elements in the group
2) Realized that some elements had not been discovered so he left gaps for them.
78
Because Mendeleev was so confident that his table was correct what did he do?
He predicted the properties of the undiscovered elements based on other elements in the same groups.
79
In the perodic table elements are laid out in order of what?
of increasing atomic (proton) number
80
Metals are found where in the Periodic table?
Left
81
Non-Metals are found where in the Periodic table?
Right
82
Vertical columns in the periodic table are called what?
Groups
83
What does the group number tell you?
The number of electrons in the outer shell
84
What are rows called in the periodic table?
Periods
85
Chlorine reacts in a similar way to bromine. Suggest a reason why.
Both in the same group and the same amount of electrons in their outer shell.
86
Sodium readily forms 1+ ions. Suggest what ions potassium forms and explain why?
It will produce 1+ ions because they are in the same group and so will react similar.
87
Metals form what type of ions when reacted?
Positive ions
88
Non- metals form what type of ions when reacted?
Negative ions.
89
Where are metals located?
Bottom left
90
Where are non-metals located?
Top right.
91
When metal reacts what happens?
They lose electrons to achieve a full outer shell
92
State whether metals generally form positive or negative ions. Explain why they form these ions with reference in the periodic table?
Positive ions. Metals can be towards the left of the periodic table, where they don't have many electrons in their outer shell, or they can be towards the bottom of the periodic table where the outer electrons are a long way from the nucleus so feel a weak attraction. This means that not much energy is needed to remove the outer electrons and form a positive ion.
93
State 3 properties of metals.
1) They are strong (hard to break) but can be bent or hammered into different shapes (malleable)
2) They are great at conducting heat and electricity
3) They have high boiling and melting points
94
State 3 properties of non-metals.
1) Dull-looking
2) more brittle
3) aren't always solids at room temperature
95
What are group 1 metals known as?
The alkaline metals
96
How many electrons do the alkaline metals have in their outer shell and what does this mean?
They have one electron in their outer shell meaning that when they react they have to lose one electron to gain a full outer shell, by losing one electron they become 1+ ions.
97
What are three properties of group one metals?
1) they have a low density
2) soft (can cut with a knife)
3) Shiny when cut, but usually dull because they react quickly with oxygen in the air, which quickly tarnishes them into a dark dull colour.
98
What are three trends as you go down the group 1 (alkali metals)?
1) Increasing reactivity
2) Lower melting and boiling points
3) High relative atomic mass.
99
Why as you go down the group 1 metals their is an increase of reactivity?
The outer electron is more easily lost as the attraction between the nucleus and electron decreases, because the electron is further away from the nucleus the further down the group you go.
100
What do Alkaline metal form with non metals?
Ionic compounds , group 1 metals don't need that much energy to lose an electron to form a outer shell, so they only ever react to form ionic compounds which are generally white salts that dissolve in water to form colorless solutions.
101
Group 1 metals react with water to form what?
Metal hydroxide + Hydrogen
102
Potassium + water produces what?
Potassium hydroxide + hydrogen
103
sodium + water produces what?
Sodium hydroxide + hydrogen
104
What the symbol for hydroxide?
OH
105
Write the symbol equation for Potassium + water --- Potassium hydroxide + hydrogen?
k + H20 ---- KOH + H2
106
How do group 1 metals react with water?
Very vigrously
107
When Lithium sodium and potassium react with water what happens?
Fizzing and bubbles and also float and move on surface.
108
What is produced when an alkaline metal are heated when it reacts with chlorine?
It produces Metal chlorides
109
Do group 1 metals react vigorously with Chlorine gas when heated?
Yes
110
As you go down the Group one metals does the reaction with chlorine become more vigorous or not?
Becomes more vigorous.
111
Sodium + chlorine produces what?
Sodium chloride
112
What is the symbol equation of Sodium + chlorine --- Sodium chloride?
Na + Cl ---- NACI
113
What happens when Group 1 metals react with Oxygen?
They produce metal oxides.
114
Will group one metals always form the same oxide?
No it depends on the group one metal?
115
Lithium + oxygen produces what?
lithium oxide.
116
Sodium + oxygen reacts to form?
Sodium oxide + sodium peroxide.
117
Potassium + oxygen reacts to form?
Potassium peroxide (k202) + Potassium superoxide (KO2)
118
What observations do you see when group one metals react with oxygen?
1) At room temperature in the air they react with oxygen to form a white metal oxide which coats the outside of the metal
2) When heated they burn vigorously, releasing a lot of light, as well as forming a white smoke which is metal oxide.
119
The word equation for the reaction is:
lithium + water ⟶ lithium hydroxide + hydrogen
The lithium floated on the water.
State two other observations that the student would see during the reaction.
1) hydrogen bubbles
| 2) lithium moves on the surface of the water
120
Potassium is more reactive than sodium.
State 2 differences between the reaction of potassium with water compared with
the reaction of lithium with water from Question 1?
1) potassium reacts more quickly/more vigorously
| 2) potassium burns with a lilac flame
121
Explain why potassium is more reactive, in terms of electronic structure than sodium?
In potassium the outer shell electron is further away from the nucleus than lithium, therefore the outer shell electron is less strongly attracted to the nucleus as there is more shielding and so the outer shell electron in potassium is more easily lost than lithium.
122
What are group 7 metals known as?
Halogens
123
How many electrons do halogens have in their outer shell?
7
124
Are halogens metals or non metals?
Non metals
125
What color gas is fluorine?
Yellow Poisonous gas
126
What color gas is chlorine?
dense green gas.
127
What color gas is Iodine?
Purple vapour or dark grey crystalline solid.
128
What do group 7 non metals exist as?
as Molecules which asre pairs of atoms
129
What is symbol of F?
F2
130
What is symbol of bromine?
Br2
131
What are the 3 trends as you go down the group 7 halogens?
1) Becomes less reactive
2) Higher melting and boiling points
3) Have a higher relative atomic masses
132
Why does the halogens become less reactive when you go down the group?
It is harder to gain an electron, as the outer shell's further from the nucleus.
133
Halogens can share electrons via what?
Covalent bonding with other non metals to achieve a full outer shell e.g HCI
134
Halogens can form what with Metals?
Ionic bonds
135
What are halides?
When a metal + non-metal react to form metal halides such as NACI which are white solids which dissolve in water to form colorless solutions.
136
What is a displacement reaction in terms of halogens?
A more reactive halogen with take the less place of a less reactive halogen from a solution of its salt.
137
What happens when chlorine reacts with sodium bromide?
there will be a reaction as chlorine is more reactive than bromide, so will displace bromide.
138
What happens when chlorine reacts with sodium iodide?
there will be a reaction as chlorine is more reactive than iodine, so will displace iodide.
139
What happens when chlorine reacts with sodium chloride?
No reaction, chlorine will not react with a chloride.
140
What happens when bromide reacts with sodium chloride?
No reaction as bromide is less reactive then chlorine, so will not displace the chloride.
141
What happens when bromide reacts with sodium bromide?
No reaction as bromide will not react with bromine.
142
What happens when bromide reacts with sodium iodide?
there will be a reaction as bromide is more reactive than iodine, so will displace the iodide.
143
What happens when iodide reacts with sodium chloride?
No reaction as iodine is less reactive than chlorine, so will not displace the chloride.
144
What happens when iodide reacts with sodium bromide?
No reaction as iodine is less reactive than bromine, so will not displace the bromine.
145
What happens when iodide reacts with sodium iodide?
No reaction, as iodine will not react with an iodide.
146
What happens when chlorine reacts with sodium bromide
it produces sodium chloride + bromine
147
What is symbol of sodium bromide?
NaBr
148
What is symbol of sodium iodide?
NaI
149
What are group 0 elements known as?
Noble gases
150
How many electrons do they have in their outer shell?
8 electrons meaning they are stable
151
Which element from group 0 which have 2 electrons in their outer shell
Helium
152
Why are group 0 gases unreactive?
Because they have a full outer shell, they are inert as they don't react at all
153
Why don't group 0 elements not form molecules?
They have 8 electrons in their outer shell. they exist as monatomic gases (single atoms not bonded with each other)
154
What are group 0 elements at room temperature?
colorless gases
155
As group 0 elements are inert what does this mean?
they are non-flammable (won't set on fire)
156
What are the trends of Group 0 gases?
The boiling points of noble gases increase as you move down the group with the increasing atomic masses
157
Why does the boiling point increase as you go down group 0?
It is due to the increase in the number of electrons in each atom leading, meaning it requires a great deal more energy to overcome the intermolecular forces
158
Neon is a gas at 25' C. Predict what state helium is at this temperature?
Helium has a lower boiling point than neon as it is further up the group, so helium must also be a gas at room temperature.
159
Radon and Krypton have boiling points of -62'C and -153'C respectively. Predict the boiling point of xenon.
Xenon comes in between radon and krypton in the group so you can predict that it is boiling point would be halfway between their boiling points. (-153) + (-62) = -215
-215/2 = -107.5
So boiling point of xenon would have a boiling point of about -108 'C
160
Helium is used to fill party balloons. What properties make helium suitable for filling party balloons?
1) Less dense than air
| 2) Very unreactive
161
Argon is very unreactive. Explain why?
Argon has a full outer shell so it is stable and does not readily lose or gain electrons.
