C1 - Atomic Structure & Periodic Table

Question 1

Complete the relative mass and charge numbers of the 3 subatomic particles

Answer 1

Proton - 1 mass, +1 charge
Neutron - 1 mass, 0 charge
Electron - 0 mass, -1 charge

Question 2

What determines the size of an atom?

Answer 2

The volume of the electrons’ orbits

Question 3

23 - the atomic (proton) number
Na TRUE OR FALSE?
11 - the (relative atomic) mass number

Answer 3

False - they are the other way around.
The relative atomic mass number is the top one
The atomic number is the bottom one

Question 4

What do these tell you about an element:

a) The relative atomic mass number
b) The atomic number

Answer 4

a) The sum of protons and electrons

b) The amount of protons or electrons

Question 5

Which subatomic particle determines the element?

a) Protons
b) Neutrons
c) Electrons

Answer 5

a) Protons - once this number changes, the element changes

Question 6

What is it that makes isotopes different?

Answer 6

The amount of neutrons the element has, e.g
Carbon 12 has 6 neutrons, Carbon 13 has 7 neutrons
The 12/ 13 refers to their top number (the mass number)

Question 7

What is the formula for relative atomic mass?

Answer 7

Sum of abundance of all the isotopes

Question 8

Copper has 2 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

Answer 8

ANSWER - 63.6

69. 2 x 63) + (30.8 x 65
- ———————————–
69. 2 + 30.8

Question 9

What does abundance mean?

Answer 9

Amount

Question 10

What is the difference between mixtures and compounds?

Answer 10

Compounds are when elements react together, mixtures are just when their held together, but aren’t chemically combined - they are easily separated (without need of a chemical reaction to separate them like compounds need)

Question 11

Give the definition of a compound

Answer 11

Substances formed from 2 or more elements, the atoms of each are in fixed proportions throughout the compound and held together by chemical bonds

Question 12

Are the nuclei affected when atoms bond?

Answer 12

No - only the electrons

Question 13

What is ionic bonding?

Answer 13

A compound formed between a metal and a non-metal consists of ions. The metal atoms lose electrons to form positive ions, and the non-metal atoms gain electrons to form negative ions. The opposite charges means their strongly attracted to each other.

Question 14

OPPOSITE CHARGES

Answer 14

ATTRACT

Question 15

Give some examples of ionically bonded substances and covalently bonded substances

Answer 15

IONIC - Sodium chloride
IONIC - Magnesium oxide
IONIC - Calcium oxide
COVALENT - hydrogen chloride gas
COVALENT - carbon monoxide
COVALENT - water

Question 16

What is covalent bonding?

Answer 16

A compound formed from non-metals consists of molecules. Each atom shares an electron with another atom.

Question 17

What are these compounds?

a) NH3
b) H2SO4
c) CaCl2
d) Na2CO3
e) HCl
f) CH4
g) C6H12O6

Answer 17

a) Ammonia
b) Sulfuric acid
c) Calcium chloride
d) Sodium carbonate
e) Hydrochloric acid
f) Methane
g) Glucose

Question 18

Balance the equation:

H2SO4 + NaOH = Na2SO4 + H2O

Answer 18

H2SO4 + 2 NaOH = Na2SO4 + 2 H2O

Question 19

Give an example of a mixture

Answer 19

Air

Crude oil

Question 20

The properties of a mixture are just a mixture of the properties of the separate parts - the chemical properties of a substance aren’t affected by it being part of a mixture. True or false?

Answer 20

True - Stuff still reacts with parts in the air even if it’s with other stuff too

Question 21

Explain why you shouldn’t use a pen to draw a line on the filter paper in chromatography (1 mark)

Answer 21

The pen ink may dissolve in the solvent and rise in the filter paper

Question 22

Put this in the correct order of the method for paper chromatography:

1) Place a lid on the container to stop the solvent from evaporating
2) Make sure the ink isn’t touching the solvent - you don’t want it to dissolve
3) The end result is a pattern of spots called a chromatogram
4) Draw a line in pencil near the bottom of a sheet of filter paper
5) If any dyes in the ink are insoluble in the solvent you used, then they’ll stay on the baseline
6) Add a spot of ink to the line and place the sheet in a beaker of solvent (such as water)
7) The solvent used depends on what’s being tested. Some compounds dissolve well in water, but sometimes other solvents (like ethanol) are needed
8) The solvent seeps up the paper, carrying the ink with it
9) Each different dye in the ink will move up the paper at a different rate so they will separate. Each dye will form a spot in a different place - 1 spot = 1 dye
10) When the solvent has nearly reached the top of the paper, take it out and leave it to dry

Answer 22

4) Draw a line in pencil near the bottom of a sheet of filter paper
6) Add a spot of ink to the line and place the sheet in a beaker of solvent (such as water)
7) The solvent used depends on what’s being tested. Some compounds dissolve well in water, but sometimes other solvents (like ethanol) are needed
2) Make sure the ink isn’t touching the solvent - you don’t want it to dissolve
1) Place a lid on the container to stop the solvent from evaporating
8) The solvent seeps up the paper, carrying the ink with it
9) Each different dye in the ink will move up the paper at a different rate so they will separate. Each dye will form a spot in a different place - 1 spot = 1 dye
5) If any dyes in the ink are insoluble in the solvent you used, then they’ll stay on the baseline
10) When the solvent has nearly reached the top of the paper, take it out and leave it to dry
3) The end result is a pattern of spots called a chromatogram

Question 23

What does soluble mean?

Answer 23

Able to dissolve in water. The opposite of this is insoluble - where it cannot dissolve in water

Question 24

Give the name of the pattern of dots created at the end of chromatography

Answer 24

A chromatogram

Question 25

Which method of separation should be used to separate: a) Insoluble solids from liquids b) soluble solids from solutions c) liquids d) solutions (both the soluble solid and the liquid at the end)

Answer 25

a) Filtration (filter paper) b) Evaporation or Crystallisation c) Fractional distillation d) Distillation

Question 26

What is the method for the separating technique of crystallisation?

Answer 26

1) Pour the solution into an evaporating dish and gently heat. Some will evaporate and the solution will beome more concentrated 2) Once some of the solvent has evaporated or when crystals start to form, remove the heat and let it cool 3) The salt should start to form crystals as it becomes insoluble in the cold, highly concentrated solution 4) Filter the crystals from the solution, and leave them to dry in a warm place (a drying oven or desiccator)

Question 27

Give the method for the separation technique of evaporation

Answer 27

1) Pour the solution in an evaporating dish 2) Slowly heat the solution (with a bunsen burner, water bath or electric heater). The solvent will evaporate and the solution will become more concentrated. Eventually, crystals will begin to form 3) Keep heating the evaporating dish until only dry crystals are left - the soluble solid from the solution as all the water has evaporated

Question 28

Why would you have to use crystallisation instead of evaporation?

Answer 28

If the salt decomposes when heated, then crystallisation is necessary

Question 29

What can be used to separate rock salt (a mixture of salf and sand?

Answer 29

Filtration and evaporation (crystallisation if you want larger crystals), as water can be added, the sand filtered out then the salt water solution evaporated/ crystallised.

Question 30

What is distillation used for?

Answer 30

Simple distillation is used to separate solutions | Fractional distillation is used to separate a mixture of liquids

Question 31

Talk through the basic steps of distillation

Answer 31

1) The solution is heated 2) Part of solution with a lower boiling point evaporates first 3) Vapour cools & condenses in the condenser/ cooling column, and is collected 4) The rest of the solution (the solid, if it's sea water) gets left in the flask 5) Pure liquid is collected at the other end once it leaves the cooling tube thing

Question 32

How does the basis for fractional distillation work?

Answer 32

It separates the liquids based on their boiling points - with simple distillation it will only work if the boiling points aren't close together

Question 33

Where is the coolest part of the column in distillation?

Answer 33

The top - as it is furthest from the heat

Question 34

In the condensing tube/ condenser, which way does the water go in and out?

Answer 34

WATER OUT ^ ============= WATER IN ^ They both go upwards

Question 35

Complete the sentence: | In fractional distillation, the liquid with the highest boiling point...

Answer 35

Either remains in the flask or gets separated last

Question 36

Fill the blanks: With __________ distillation, liquids with higher _______ points might also start to _________ early on. But the column is ______ towards the top, so they will only get part way up before __________ and running back down to the _____ again.

Answer 36

``` Fractional Boiling Evaporate Cooler Condensing Flask ```

Question 37

What is the fractionating column?

Answer 37

It goes on top of the flask, and is filled with glass rods for some reason.

Question 38

One no more of the first liquid produced by fractional distillation is produced, how do you start to separate the next liquid in the mixture?

Answer 38

You raise the temperature until the next liquid reaches the condenser

Question 39

John Dalton said what about atoms at the start of the 19th century?

Answer 39

That they were solid spheres - plum pudding model not belief back then

Question 40

Who concluded that atoms must have electrons due to his measurements of charge and mass?

Answer 40

J J Thompson - 1897

Question 41

The plum pudding model shows the atom as a ball of positive charge with electrons in it. True or false?

Answer 41

True - after electrons were discovered in 1897 by J J Thompson

Question 42

Who discovered these subatomic particles and in what Order?

Answer 42

1) Electrons - J J Thompson 2) Protons - Ernest Rutherford 3) Neutrons - James Chadwick

Question 43

How did Ernest Rutherford disprove the plum pudding model?

Answer 43

He fired alpha particles at a thin sheet of gold expecting them to go straight through or deflect a little, because the positive charge was thought to be very spread out through the atom. But this did not happen, so he invented the nuclear model of the atom - the positvely charged nucleus at the centre and a negative "cloud" of electrons surrounding it (so most of the atom is empty space). When alpha particles came near the concentrated, positive charge of the nucleus, they were deflected. When the nucleus collided, they were deflected backwards. Otherwise, they passed through the empty space

Question 44

What did Bohr change to Rutherford's nuclear model of the atom?

Answer 44

Instead of it being a cloud of negative charge caused by the electrons, he suggested that electrons orbit in fixed shells.

Question 45

What is the modern model of the atom known as?

Answer 45

The nuclear model

Question 46

Fill the blanks: Further experiments by Ernest __________ and others showed that the nucleus can be _______ into smaller particles, each with the same ______ as a ________ _______. These subatomic particles were named _______

Answer 46

``` Rutherford Divided Charge Hydrogen nucleus Protons ```

Question 47

Who discovered neutrons?

Answer 47

James Chadwick, around 20 years after scientists accepted the existence of nuclei in atoms

Question 48

What are the 5 electron shell rules? (with these hints) 1) What electrons do 2) The lowest energy levels 3) Amount of electrons 4) Happy atoms 5) Why atoms react

Answer 48

1) Electrons always occupy shells (sometimes called energy levels) 2) The lowest energy levels are always filled first - these are the ones closest to the nucleus 3) Only a certain number of electrons are allowed in each shell - 1st shell has 2 electrons, 2nd shell on has 8 electrons 4) Atoms are happier when they have full electron shells (like the noble gases in group 0/8) 5) In most atoms, the outer shell is not full and this makes the atom want to react to fill it.

Question 49

Up to what point do atoms' shells become diffcult to draw?

Answer 49

After the 20th element Hydrogen, helium, lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, neon, sodium, magnesium, aluminium, sillicon, phosphorus, sulfur, chlorine, argon, potassium and calcium

Question 50

How were elements arranged in the early 1880's? What was the problem with this? How are they arranged now?

Answer 50

By atomic mass - did not consider their properties | By atomic number now (after electrons and protons discovered - 20th century)

Question 51

What is atomic mass?

Answer 51

The average mass of one atom of an element

Question 52

When and how did Mendeleev arrange his Table of Elements?

Answer 52

1869. He mainly put elements in order of atomic mass, but switched the order if the properties meant it should be changed. There were also gaps to make sure that elements with similar properties stayed in the same groups (also, they indicated undiscovered elements)

Question 53

When were isotopes discovered? a) 19th century b) 20th century c) 21st century

Answer 53

b) 20th century - confirmed Mendeleev was right in considering properties when organising elements

Question 54

In the periodic table: a) the further across you go... b) metals are on the... c) elements with similar properties form... d) all group 1 elements are... e) elements react more vigorously as you go... f) the rows are called... g) these represent

Answer 54

a) the more protons are there b) left & bottom - 2 elements), and non metals are on the right (more metals) c) columns called groups d) metals and react similarly e) down the groups f) periods g) another full shell of electrons

Question 55

Non metals form positive ions when they react, metals form negative ions when they react. True or false?

Answer 55

False - usually non-metals form negative ions, metals form positive atoms

Question 56

Fill the blank: | Metals to the left of the electronic table don't have as many electrons to remove compared to the metals...

Answer 56

Towards the bottom of periodic table (as they have electrons a long way from the nucleus so feel a weaker attraction) Both these effects mean not much energy is needed to remove the electrons, so it's possible for the elements to react and form positive ions with a full outer shell

Question 57

If an atom loses electron, what is the charge?

Answer 57

Positive overall - it becomes a positive ion

Question 58

How do non-metals generally complete their full outer shell? Why is it s difficult for them to become positive ions?

Answer 58

By either sharing or gaining electrons. | Because they have lots of electrons they need to lose to become a positive ion

Question 59

What are 3 similar and basic properties of metals that have metallically bonded?

Answer 59

They're strong (hard to break) but malleable They're great at conducting heat and electricity They have high boiling and melting points

Question 60

Non metals form a variety of different structures, so...

Answer 60

They have a wide range of chemical properties

Question 61

As non-metals don't have metallic bonding, what properties do they OFTEN/ GENERALLY show when they bond?

Answer 61

``` They are dull looking More brittle Aren't always solids at room temperature Don't conduct electricity Lower density ```

Question 62

What are group 1 elements? (a few words) | Name some

Answer 62

Reactive, soft metals | Alkali metals - lithium, sodium, potassium, rubidium, caesium and francium

Question 63

What makes Alkali metals so reactive? Which are more reactive?

Answer 63

Group 1 metals have only 1 electron on their outer shell, so they are very reactive and have similar properties. The further down the column you go, the more reactive they become because the shells get further away from the nucleus, so more likely to react (sodium i less reactive than caesium)

Question 64

Name some trends as you go down the group 1 column.

Answer 64

Increase in reactivity (outer electron is more easily lost) Lower melting & boiling points Higher relative atomic mass

Question 65

What do alkali metals form when they react with non metals?

Answer 65

Ionic compounds - generally white solids that dissolve in water to form colourless solutions

Question 66

What is produced when group 1 elements react with water?

Answer 66

Hydrogen, the energy given out when they react increases as you go down the group (for potassium & below, there's enough to ignite hydrogen - why a lilac flame is seen when potassium experiment occurs) Also, they form hydroxides that dissolve in water to give alkaline solutions

Question 67

Balance this equation, and what experiment this is: | Na(s) + H2O(l) = NaOH(aq) + H2(g)

Answer 67

2Na + 2H2O = 2NaOH + H2 Sodium + water = Sodium hydroxide + hydrogen Putting a group 1 element in water (the sodium can be replaced with any alkali metal and it would be the same)

Question 68

What will reacting a group 1 element with chlorine produce?

Answer 68

A salt (group 1 metals react vigorously when heated in chlorine gas to form white salts called metal chlorides) THINK NaCl!

Question 69

What happens when a group 1 element reacts with oxygen?

Answer 69

It will form a metal oxide, different depending on the metal used: Lithium reacts to form lithium oxide (Li2O) Sodium reacts to form a mixture of sodium oxide (Na2O) and sodium peroxide (Na2O2) Potassium reacts to form a mixture of potassium peoxide (K2O2) and potassium superoxide (KO2)

Question 70

What are group 7 elements known as? Give a few words to describe them, and name some

Answer 70

Halogens - all non-metals with coloured vapours. Fluorine, chlorine, bromine, iodine (all those examples are poisinous too, dunno about astatine)

Question 71

All halogens exist as pairs of atoms. True or false?

Answer 71

True - F2, Cl2, Br2 I2 etc

Question 72

Give some qualities of: a) Fluorine b) Chlorine c) Bromine d) Iodine

Answer 72

a) Very reactive, poisonous yellow gas b) Fairly reactive, poisonous dense green gas c) Dens, poisonous, red-brown volatile liquid d) Dark grey crystalline solid or a purple vapour (has poison symbol too, so...)

Question 73

As you go down the group, what are some qualities of the group 7 elements?

Answer 73

Become less reactive (harder to gain one more electron as the outer shell is far away Higher melting and boiling points Higher relative atomic masses

Question 74

What can halogens form?

Answer 74

Molecular compounds - they share electrons in covalent bonding with other non-metals. The compounds that form when halogens react with non-metals all have simple molecular structures

Question 75

Halogens form what type of bond with metals? a) Compound b) Ionic c) Metallic

Answer 75

b) Ionic - the halogens form 1- ions called halides. The compounds that form have ionic structures I think, they only/mostly do this with group 1 metals

Question 76

Complete the sentence: | Reactive halogens will displace...

Answer 76

less reactive ones e.g. chlorine can displace bromine and iodine from an aqueous solution of its salt. Bromine will also displace iodine because of the trend in reactivity (whatever that means)

Question 77

Give a few words to describe group 0 elements, then name a few

Answer 77

Noble gases are all inert, colourless gases. | Helium, neon, argon, krypton, xenon, radon

Question 78

Give some qualities of group 0 elements as you go down their column

Answer 78

The boiling points increase (increase in electron amounts, greater intermolecular forces between them) Increasing relative atomic mass

Question 79

What does monatomic gases mean? Which group does this this apply to?

Answer 79

Group 0 - Single atoms not bonded to each other

Question 80

What are all group 0 elements at room temperature?

Answer 80

Colourless gases

Question 81

Noble gases are flammable - true or false?

Answer 81

False - they won't set on fire as they are inert (as they have complete shells)

Question 82

Exam questions: 1) Does xenon or neon have a higher boiling point? (1 mark) 2) Argon is not very reactive. Use your knowledge of its electronic structure to explain why (2 marks)

Answer 82

1) xenon (because it is further down the column) 2) Argon has a full outer shell (1 mark) So it's electronically stable and does not readily lose or gain electrons (1 mark)