1) Key Concepts in Chemistry Flashcards

1
Q

What are compounds?

A

Combined atoms of different elements

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

What is the smallest piece of an element that can exist?

A

An atom

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

What are the key features of chemical compounds?

A

Compounds are broken up or formed
At least 1 new substance is created
Measureable energy change
No atoms are created or destroyed

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

What type of equation must be balanced?

A

Symbol equations

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

What is the order of atomic models?

A

Dalton’s model
Thomson’s plum pudding
Rutherford’s nuclear model
Modern model

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

What is the atomic number?

A

Number of protons in the atom

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

What is the mass number?

A

Number of protons + neutrons

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

What is the top number of an atom?

A

Mass number

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

What are isotopes?

A

Atoms with the same number of protons but a different number of neutrons

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

What are the isotopes of hydrogen?

A

Protium
Deuterium
Tritium

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

What is the name for a specific nucleus that contains a certain number of protons and neutrons?

A

Nuclide

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

What did J.J.Thomson discover?

A

Electrons

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

What was J.J.Thomson’s model?

A

Plum pudding model

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

What did Rutherford discover?

A

Alpha particles could bounce off atoms
Atom’s mass concentrate in centre
Protons

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

What was Rutherford’s model?

A

Nuclear model

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

Who discovered neutrons?

A

James Chadwick

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

What is the relative atomic mass?

A

The average mass of all of the isotopes of an element

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

What is the formula for Ar?

A

(Isotope abudance x isotope mass number) / isotope abundance

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

What does Ar mean?

A

Relative atomic mass

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

What is the isotope abundance?

A

How often each isotope of an element is found

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

What are the rows of the periodic table called?

A

Periods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the columns of the periodic table called?

A

Groups

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

What does the group number equal?

A

The number of electrons in an atom’s outer shell

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

Who was the first to devise a periodic table?

A

John Newlands

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

Who predicted the undiscovered elements of the periodic table?

A

Mendeleev

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

How do we rank elements today?

A

By their atomic number (number of protons)

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

Where are metals found on the periodic table?

A

The left side

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

What happens when metals react?

A

They lose 1 or more electrons to form positive ions

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

What are properties of metals?

A

High melting and boiling points
Good conductors of heat and electricity
Solids at room temperatrue (except mercury)

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

Where are non-metals found on the periodic table?

A

The right side

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

What happens when non-metals react?

A

They gain electrons to form negative ions

Or share electrons to form neutral molecules

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

What are properties of non-metals?

A

Lower melting and boiling points than metals
Often found as gases
Generally do not conduct heat or electricity

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

How does energy change as you get closer to an atom’s nucleus?

A

Closer to nucelus = lower energy level

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

What is the filled electron configuration?

A

2,8,8

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

What is the difference between molecules and an element?

A

Molecules are a substance with two or more atoms (O2)

Elements are pure substances of the same atom (O)

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

What can dot and cross diagrams show?

A

Electrons being transferred and ions formed

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

What do square brackets and a charge represet in dot and cross diagrams?

A

Ions

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

What is a cation?

A

A positive ion

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

What is an anion?

A

A negative ion

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

What does a cation have?

A

More protons than electrons

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

What does an anion have?

A

More electrons than protons

42
Q

What is ionic bonding?

A

When atoms trade electrons to both have full outer shells

43
Q

What happens to group 1 metals during ionic bonding?

A

They lose 1 electron

44
Q

What happens to group 2 metals during ionic bonding?

A

They lose 2 electrons

45
Q

What happens to group 6+7 non-metals during ionic bonding?

A

They gain electrons

46
Q

What happens to group 0 noble gases during ionic bonding?

A

They are unreactive as they have a full outer shell

47
Q

How are cations created?

A

When an atom or molecules loses electrons

48
Q

How are anions created?

A

When an atom or molecule gains electrons

49
Q

What happens to an atom’s charge if it gains electrons?

A

Negative charge

50
Q

What do ionic compounds made from 2 different elements end in?

A

-ide

51
Q

What do ionic compounds made from 3 or more different elements end in?

A

-ate

52
Q

What does K+ and O2- form?

A

K2O

We need two K+ ions to cancel out the 2- charge of the oyxgen

53
Q

When do we use brackets in ionic compound formulas?

A

When there are multiple groups of atoms

54
Q

What is the overall charge of an ionic compound formula?

A

0

55
Q

What are ionic lattices?

A

Giant structures held together by strong electrostatic forces between cations and anions

56
Q

What are electrostatic forces also called?

A

Ionic bonds

57
Q

When are covalent bonds formed?

A

When 2 non-metals share pairs of electrons

58
Q

Why are covalent bonds strong?

A

The shared electrons are attracted to the nucelus of both atoms

59
Q

What can covalently bonded structures be?

A

Small molecules
Large molecules
Giant covalent structures

60
Q

How do double and triple bonds compare to single covalent bonds?

A

They are stronger and require more energy to break

61
Q

What group of elements is joined by triple bonds?

A

Group 5 as each atom needs to gain 3 electrons to obtain a full outer shell

62
Q

What are properties of ionic compounds?

A

High melting and boiling points
Don’t conduct electricity when solid
Conduct electricity if liquid or in solution

63
Q

Why can’t solid ionic compounds conduct electricity?

A

The ions in the lattice are fixed in shape

64
Q

What are intermolecular forces?

A

Weak forces found between small molecules

65
Q

How strong are intermolecular forces?

A

Weak and easy to break

66
Q

What does weak intermolecular forces mean for small covalent molecules?

A

They have low melting and boiling points

Often liquids or gases at room temperature

67
Q

What are intramolecular bonds?

A

Strong covalent bonds found within small molecules

68
Q

How does the size of a molecule affect the attraction to other molecules?

A

Bigger molecules attract other molecules with stronger intermolecular forces

69
Q

What are properties of giant covalent structures?

A

No specific formula
Very high melting points
1 large molecule

70
Q

Why don’t giant covalent structures have a formula?

A

They can be any size

71
Q

What ways can you represent covalent bonds?

A

Lines
Ball and stick
Dot and cross with shells
Dot and cross without shells

72
Q

What is a limitation of ball and stick diagrams?

A

Atoms are much closer than the diagram shows

73
Q

What is a limitation of dot and cross diagrams with shells?

A

It shows electrons differently for each atom when they are actually the exact same

74
Q

What properties does diamond have?

A

Doen’t conduct electricity
Covalent bonds
High melting point
Hard

75
Q

How many other carbon atoms is each diamond carbon atom bonded to?

A

4

76
Q

What is an allotrope?

A

A form of an element

77
Q

What are properties of graphite?

A

Soft
Covalent bonds
Conducts electricity

78
Q

How many other carbon atoms is each graphite carbon atom bonded to?

A

3 creating 1 delocalised electron

79
Q

Why is graphite soft and used as a lubricant?

A

Carbon atoms form layers of hexagonal rings with weak intermolecular forces keeping the layers together

80
Q

What are fullerenes?

A

Molecules of carbon atoms that take up hollow structures

81
Q

What is the structure of fullerenes?

A

Usually hexagonal rings

Can be pentagonal or heptagonal

82
Q

What is buckminsterfullerene?

A

A spherical shape

First fullerene discovered

83
Q

What are uses of fullerenes?

A

Catalysts
Lubricants
Drug transport vehicles to our bodies

84
Q

What are carbon nanotubes?

A

Cylindrical fullerenes

85
Q

Why are cyclindrical fullernes strong?

A

Strong covalent bonds between carbon atoms

86
Q

What are uses of cylindrical fullerenes?

A

Electronics
Nanotechnology
Strengthening materials

87
Q

What is the formula for buckminsterfullerene?

A

C60

88
Q

What is the relative formula mass the sum of?

A

All relative atomic masses of each atom in the formula

89
Q

What is the empirical formula?

A

The simplest ratio of ions possible

90
Q

What is the molecular formula?

A

The actual amount of atoms which make up a molecule

91
Q

What is the molecular and empirical formula for glucose?

A

C6H12O6

CH2O

92
Q

What are the steps for the experiment for calculating empirical formula?

A

1) Measure mass of solid going to be reacted
2) React solid with oxygen in air by heating
3) Find mass of product
4) Calculate mass of oxygen gained (final mass - initial mass)
5) Use mass of solid and oxygen to calculate empirical formula (divide mass by Ar)

93
Q

What units can concentration be measured in?

A

g / dm^3

mol / dm^3

94
Q

What is the formula for concentration?

A

concentration (g/dm^3) = mass (g) / volume (dm^3)

95
Q

What is the Avogadro constant?

A

6.02 x 10^23

96
Q

What is 1 mole of a substance equal to?

A

The relative formula mass (Mr)

97
Q

If the relative atomic mass of carbon is 12, what is the mass of 1 mole of carbon?

A

12g

98
Q

What is the equation for moles?

A

Moles = mass / Mr

99
Q

What is a limiting reactant?

A

A reactant that is completely used up

100
Q

How do we reduce the uncertainty of results?

A

Take multiple reading and calculate an average