Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

GCSE Chemistry > Topic 1: Key Concepts in Chemistry > Flashcards

Topic 1: Key Concepts in Chemistry Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards GCSE Religious Studies - Edexcel Route A flashcards GCSE Religious Studies - Eduqas Route A flashcards GCSE Geography - AQA flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards GCSE Religious Studies - Edexcel Route B flashcards GCSE Religious Studies - Eduqas Route B flashcards
1
Q

What does a chemical formula show?

A

The proportion of atoms of each element in a compound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does a chemical equation show?

A

The overall change in a reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does the state symbol (s) represent?

A

Solid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does the state symbol (l) represent?

A

Liquid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does the state symbol (g) represent?

A

Gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the state symbol (aq) represent?

A

Aqueous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What does aqueous mean?

A

Dissolved in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the chemical formula of ammonia?

A

NH₃

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the chemical formula of ammonium?

A

NH₄⁺

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the chemical formula of hydroxide?

A

OH¯

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the chemical formula of nitrate?

A

NO₃ ¯

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the chemical formula for carbonate?

A

CO₃ ²¯

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the chemical formula for sulfate?

A

SO₄ ²¯

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What does an ionic equation show?

A

Only the particles that react and the products they form

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What do ionic equations not include?

A

The aqueous ions that are present on both sides of the equation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What must an ionic equation show on the compounds or elements?

A

Their ionic charges

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are hazard symbols?

A

Symbols that warn you about the dangers of a substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is a risk assessment?

A

Identifying the hazards their risks and suggest ways to reduce risks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When should a risk assessment be made?

A

Before the reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

IN PERSON FLASHCARDS MADE FOR THE HAZARD SYMBOLS

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe how the model of the atom has changed overtime

A
  1. John Dalton described atoms as solid spheres
  2. Plum pudding model - ball of positive charges containing small electrons
  3. Nuclear model - positive nucleus surrounded by a cloud of electrons and mostly empty space
  4. Bohr model - electrons orbit the nucleus in fixed shells
  5. Nucleus contains protons and neutrons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the relative mass and relative charge of protons,electrons and neutrons?

A

Relative charge | Relative mass |
————————————————
Protons | +1 | 1 |
Neutrons | 0 | 1 |
Electrons | -1 | 0.0005 |

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Do atoms have a charge or no? Why?

A

No - they have the same number of protons and electrons so they cancel each other out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Where is most of the mass in an atom?

A

In the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is a nuclear symbol used for?

A

Used to describe atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the bigger number on an element in the periodic table known as?

A

The mass number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the smaller number on an element in the periodic table known as?

A

The atomic number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the mass number equal to?

A

Mass number = number of protons + number of neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the atomic number equal to?

A

Atomic number = the number of protons in an atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the amount of protons in an atom equal to?

A

Number of protons = number of electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How to calculate number of neutrons using the mass number and atomic number?

A

Number of neutrons = mass number of - atomic number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How to calculate number of neutrons using the sum of number of protons and number of neutrons?

A

Number of neutrons = (protons + neutrons) - number of protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What are elements?

A

Substances made up of atoms with the same number of protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Why does each element have a unique atomic number?

A

As each element has a different number of protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is an isotope?

A

An atom of an element with the same number of protons but different number of neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is relative atomic mass (Ar)?

A

The average mass of one atom of an element, compared to 1/12 of the mass of one atom of carbon-12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How to calculate relative atomic mass (Ar)?

A

Ar = (mass x abundance) + (mass x abundance) / 100

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How did Mendeleev originally group the periodic table?

A

Using the atomic mass of the elements - to group them by chemical properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Why did Mendeleev swap some elements around?

A

When ordering by atomic mass didn’t fit the pattern of chemical properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

Why were some of the atomic masses on Mendeleevs table wrong?

A

He wasn’t aware of the presence of isotopes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

Why did Mendeleev leave gaps in his periodic table?

A

To keep elements with similar properties together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What did Mendeleev predict the existence of? How?

A

Eka-silicon - used other elements in the columns to find gaps and predict

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

How is the modern periodic table organised?

A

By increasing atomic number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

What are horizontal rows on the modern periodic table called?

A

Periods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

What are vertical rows on the modern periodic table called?

A

Groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

What does the position of an element in the periodic table show you?

A

The number of electrons in their outer shell and how many shells they have

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

What does the group number tell you about the electronic configuration of an atom?

A

The number of electrons in the outer shell
E.g. group 7 like fluorine have 7 electrons in outer shell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

What does the period number tell you about the electronic configuration of an atom?

A

The number of shells the atom has

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

What is the maximum electronic configuration possible?

A

2.8.8.2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

What are the 2 ways electronic configurations can be shown?

A
  1. Diagrams and drawing the atom
  2. Through number e.g. 2.8.6
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

What is an ion?

A

A charged particle made when electrons are transferred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

What type of electron transfer do metals have when they form ions?

A

They lose electrons and form positive ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

What is a cation?

A

Positive ion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

What is an anion?

A

Negative ion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

What does the charge on an ion show?

A

The number of electron gained or lost

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

What type of electron transfer do non metals have when they form ions?

A

They gain electrons to form negative ions

57
Q

If an ion has a negative charge, what does this mean?

A

They have gained electrons - electrons have a negative charge so when they have more electrons than protons, they become negatively charged

58
Q

If an ion has a positive charge, what does this mean?

A

They have lost electrons - electrons have a negative charge so when they less more electrons than protons, they become positively charged

59
Q

What charge does each group have when become an ion?

A

Group 1: 1+
Group 2: 2+
Group 3: 3+
Group 4: varies, there’s no trend
Group 5: 3-
Group 6: 2-
Group 7: 1-

60
Q

What is the way to find out the ionic formula of a compound if you have the ionic charges of each element?

A

Drag and drop method:
1. Find the ionic charges of each element using periodic table
2. Put the ionic charge of each element onto the other element

E.g. if it’s sodium sulphide:
1. Sodium has a charge of 1+ and sulfur has a charge of 2-
2. The ionic formula will therefore be Na₂S

61
Q

If a compound ends in -ate what does this mean?

A

Oxygen and at least one other element are in the compound

62
Q

If a compound ends in -ide what does this mean?

A

Only one element is in the compound
EXCEPT FOR HYDROXIDE IONS

63
Q

What is an ionic bond?

A

The electrostatic attraction between oppositely charged ion

64
Q

When are ionic bonds formed?

A

When electrons are transferred from metal atoms to non metal atoms

65
Q

Is ionic bonding a transfer of electrons or when the atoms share electrons?

A

When electrons are transferred

66
Q

How can ionic bonding and transfers be shown?

A

Dot and cross diagrams - one atom has dots and the other has crosses - the electrons are represented by the dot or cross

67
Q

What does ionic bonding result in?

A

Charged ions when the electrons have been transferred

68
Q

What are 3 properties of ionic compounds? Why?

A
  1. High melting and boiling points - lots of energy needed to overcome strong electrostatic forces of attraction between the ions
  2. Soluble in water
  3. Conduct electricity ONLY when they’re molten or dissolved - as ions are free to move and carry electric charge
69
Q

Why are giant ionic lattices so strong?

A

The strong electrostatic forces of attraction between oppositely charged ions act in all direction - ions are closely packed

70
Q

What are the 4 different models used to show the arrangement of atoms in a compound?

A
  1. Ball and sticks diagrams
  2. Dot and cross diagrams
  3. Displayed formula (2D)
  4. 3D model
71
Q

What do ball and stick diagrams not show?

A

Which atoms the electrons in the bonds come from
They aren’t to scale and have gaps between ions when used to show lattices

72
Q

What do dot and cross diagrams not show?

A

Relative sizes of atoms or their arrangement in space

73
Q

What does the displayed formula (2D) not show?

A

The 3D structure or sizes of atoms

74
Q

What’s the only thing the 3D model shows?

A

Outer layer

75
Q

What is a covalent bond?

A

A shared pair of electrons between two non metal atoms

76
Q

What is a covalent bond between?

A

Two non mental atoms

77
Q

Is covalent bonding a transfer of electrons or when the atoms share electrons?

A

The share of electrons

78
Q

What are simple molecular substances made up of?

A

Molecules containing a few covalently bonded atoms

79
Q

What is the size of a simple molecule?

A

Around 10^-10 m

80
Q

Are covalent bonds between atoms strong or weak in covalently bonded atoms?

A

They are strong between atoms

81
Q

Are intermolecular forces between molecules strong or weak in covalently bonded atoms?

A

Forces between molecules are weak

82
Q

What does a covalent bond result in? How?

A

A full outer shell for all of the atoms - they share electrons to have a full shell

83
Q

What does a ionic bond result in? How?

A

A full outer shell for all of the atoms - they loss or gain electrons from each other to have a full shell

84
Q

What are the 3 properties of simple molecular substances?

A
  1. Low melting and boiling points - mostly gases and liquids at room temperature - due to having weak forces in between the molecules
  2. Don’t conduct electricity - there are no charged particles in the substance to carry charge
  3. Some are soluble in water but some aren’t
85
Q

What are giant covalent structures?

A

Solids containing atoms which are all bonded to each other by strong covalent bonds

86
Q

What are 3 properties of giant covalent structures? Why?

A
  1. High melting and boiling points - lots of energy is required to overcome strong covalent bonds
  2. Don’t conduct electricity (with a couple exceptions) - no charged particles to carry charge
  3. Not soluble in water
87
Q

What are examples of giant covalent structures?

A

Diamond and graphite

88
Q

What are polymers?

A

Very long chains of covalently bonded carbon atoms

89
Q

What are the bonds between the atoms in polymers?

A

Strong covalent bonds

90
Q

What are polymers a collection of?

A

Monomers

91
Q

How are polymers written?

A

Poly(the compound)

E.g. poly(ethene)

92
Q

What are the 3 carbon allotropes?

A
  1. Diamond
  2. Graphite
  3. Graphene
93
Q

What is the bonding like in diamond?

A

Carbon atoms form 4 covalent bonds

94
Q

What is the properties of diamond?

A

Very hard

95
Q

What is the conductivity of diamond?

A

Doesn’t conduct electricity

96
Q

What is the bonding like in graphite?

A

Carbon atoms form 3 covalent bonds
No covalent bonds between layers of graphite

97
Q

What are the properties graphite?

A

Soft & slippery

98
Q

What is the conductivity of graphite? Why?

A

Conducts electricity and thermal energy - each carbon atom in it has one delocalised electron

99
Q

What are the uses of graphite?

A

Electrodes
Lubricant

100
Q

What is the bonding like in graphene?

A

Carbon atoms form 3 covalent bonds

101
Q

What are the properties of graphene?

A

Strong & light

102
Q

What is the conductivity of graphene?

A

Conducts electricity - each carbon atom in it has one delocalised electron

103
Q

What are properties of fullerenes?

A

Have a hollow shape and a large surface area

104
Q

What are nanotubes?

A

Cylindrical fullerenes

105
Q

What can nanotubes do? Why?

A

Conduct electricity - have delocalised electrons

106
Q

What is a metallic bond?

A

Two or more metals

107
Q

What are metallic bonds held by?

A

Strong electrostatic forces of attraction

108
Q

What are the 6 properties of metals? Why?

A
  1. High melting and boiling points - a lot of energy is needed to overcome strong metallic bonds
  2. High density - ions are packed close together
  3. Not soluble in water
  4. Shiny appearance
  5. Good electrical conductors - delocalised electrons can carry charge
  6. Soft and malleable - layers in metals slide over each other
109
Q

What happens to electrons in metallic bonding?

A

They lose electrons to gain a full outer shell

110
Q

What are chemical properties of non metals?

A

Outer shells are over half filled
Gain electrons to get a full outer shell

111
Q

What is relative formula mass (Mr)?

A

Sum of all the relative atomic masses of the atoms in the molecular formula (the sum of all of the mass numbers in the compound)

112
Q

What is one mole equal to?

A

One mole = 6.02 × 10²³ particles of a substance

113
Q

What is the Avogadro constant?

A

6.022 × 10²³

114
Q

What is the mass (in grams) of one mole of an atom of an element equal to?

A

The mass in grams of one mole of an atom of an element = the Ar of the element

115
Q

What is the mass (in grams) of one mole of a molecule of a compound equal to?

A

The mass in grams of one mole of molecules of a compound = the Mr of the compound

116
Q

How to calculate the number of moles?

A

Number of moles = mass in g/Mr or Ar

117
Q

How to calculate the number of particles in a mass?

A

Number of particles = number of moles x 6.022 × 10²³

118
Q

How to balance equations using masses if you know the mass of reactants and products?

A
  1. Do mass/Mr to find the moles of each substance
  2. Divide each number of moles by the smallest number of moles calculated
  3. If the results aren’t in whole numbers, multiply them by the same number to make them whole
  4. Place these numbers at the front of the chemical formulas
119
Q

What is a limiting reactant?

A

A reactant that gets completely used up in a reaction, so limits the amount of products formed when it’s been used up - leaving all other reactants in excess

120
Q

What is concentration?

A

Amount of substance dissolved in a certain volume of solution

121
Q

If the mass of solute in a reaction is increased, what happens to the concentration?

A

It increases

122
Q

If the volume of solution in a reaction is increased, what happens to the concentration?

A

It decreases

123
Q

How can concentration be calculated?

A

Concentration = mass of solute/volume of solution

124
Q

What are the units for concentration?

A

g dm^-3

125
Q

What is the empirical formula?

A

The smallest whole number ratio of atoms in a compound

126
Q

What is the molecular formula?

A

The unsimplified version of the empirical formula

127
Q

How can molecular formula be found from the empirical formula?

A
  1. Find the Mr of empirical formula
  2. Divided the Mr of the compound by the Mr of the empirical formula
  3. Multiply the atoms in empirical formula by the result
128
Q

What equipment is needed for the empirical formula experiment?

A

A crucible on a gauze containing magnesium ribbon with a lid on it
A tripod to hold the gauze and crucible
A Bunsen burner

129
Q

What 3 things need to be weighed in the empirical formula experiment?

A
  1. Empty crucible and its lid
  2. The crucible with the lid and the contents in it before heating it
  3. The crucible with the lid and the contents in it after heating it
130
Q

How can the mass of magnesium be found from the empirical formula experiment?

A

Mass of magnesium = (mass of crucible and lid + contents before heating) - (mass of empty crucible and lid)

131
Q

How can the mass of oxygen be found from the empirical formula experiment?

A

Mass of oxygen = (mass of crucible and lid + contents after heating) - (mass of crucible and lid + contents before heating)

132
Q

How can the empirical formula be worked out from the empirical formula experiment?

A
  1. Divide the mass of each element by its Ar (work out moles)
  2. Divide each result by the smallest number calculate to get the smallest whole number ratio
  3. This will give you the number of atoms of each element in its empirical formula
133
Q

How can the mass of a product formed from a given mass of a reactant be calculated?

A
  1. Write a balanced equation for the reaction
  2. Divide the mass of the reactant by its Mr to find the number of moles
  3. Use the balanced equation to find the number of moles of the product
  4. Multiplied this number of moles by the Mr of the product to work out its mass
134
Q

What is conservation of mass?

A

The idea that no atoms are created or destroyed in a chemical reaction, so the total masses of reactants and products are equal

135
Q

If a sealed reaction vessel is weighed before and after the reaction, what shouldn’t you see?

A

You shouldn’t see a change in mass - mass has been conserved as no reactants or products can escape

136
Q

If an unsealed reaction vessel is weighed before and after the reaction, what could you see?

A

You may be able to see a change in mass - either a decrease or an increase in

137
Q

When would you see a decrease in mass after a reaction has happened in an unsealed vessel? Why?

A

If a gas has been made during the reaction and has escaped the vessel - its mass is no longer accounted for as has escaped

138
Q

When would you see an increase in mass after a reaction has happened in an unsealed vessel?

A

If a gas from the air is a reactant in the reaction - its mass has thus been added to the mass in the vessel

139
Q

What are the uses of diamond?

A

Cutting tools

GCSE Chemistry (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions