Brainscape's Knowledge GenomeTM

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


See full index

CHEMISTRY > SC1: key concepts in chemistry > Flashcards

SC1: key concepts in chemistry Flashcards

1
Q

mnemonic for diatomic elements

A

I Bring Clay For Our New House:

iodine, bromine, chlorine, fluorine, oxygen, nitrogen, hydrogen

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

compound

A

a chemical combination of two or more elements

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

what does a chemical formula show?

A

how many atoms there are in each element of a compound

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

what is a covalent bond?

A

a chemical bond formed when two or atoms share electrons

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

what are covalent bonds between?

A

non-metals

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

what is an ionic bond?

A

formed when one or more electrons are transferred from one atom to another

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

what are ionic bonds between?

A

metals and non metals

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

what is an ion?

A

the charged particle formed when an atom loses or gains electrons

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

what happens in a chemical reaction?

A

the atoms of ions in reactants separate from one another and join back together in a different way to form products

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

what is an aqueous solution?

A

a solution in which water is the solvent

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

what is a precipitation reaction

A

when two soluble substances react together to make a product which is insoluble (the precipitate)

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

how is a precipitation reaction modelled?

A

with a balanced ionic equation

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

what are spectator ions?

A

ions that do not participate in a reaction

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

what is a hazard?

A

something with the potential to cause harm

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

what is a risk?

A

the chance that a hazard will cause harm

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

what is a precaution?

A

something that can be done to reduce a risk of harm

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

what is a risk assessment?

A

something that describes the hazards and risks of harm & what precautions are needed to work safely

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

what is the order of atomic structure discovery?

A
  1. john dalton
  2. j.j thompson
  3. ernst rutherford
  4. niels bohr
  5. james chadwick
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

john dalton

A

-atoms can’t be broken
-there is nothing smaller than an atom

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

j.j thompson

A

-discovered the electron (1904)
-atoms made up of small, negatively charged atoms in a positively charged area
-plum pudding model

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

ernst rutherford

A

-discovered the nucleus in 1909
-fired alpha particles (positively charged) at a thin gold lead in a vacuum, most passed through, a few were deflected, some came back
-small positively charged nucleus surrounded by empty space, electrons orbited nucleus
-nucleus was heavier than could be explained with only protons so ernst proposed neutrons
-ernst couldn’t explain why electrons didn’t collapse into the nucleus

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

niels bohr

A

-1913: discovered that electrons move around the nucleus in orbits called electron shells
-worked with rutherford
-rutherford-bohr model was supported by scientists

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

what happens when atoms absorb energy?

A

their electrons move to higher energy levels

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

mass of an electron

A

1/1835

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

what is atomic mass?

A

protons + neutrons + electrons

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

what is an atomic number?

A

the number of protons/electrons in an atom

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

what are isotopes?

A

atoms of the same element with different numbers of neutrons

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

what is RAM?

A

relative atomic mass

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

RAM facts

A

-not whole numbers
-mean relative mass of atoms of different isotopes in an element

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

what is the formula for RAM?

A

(% of isotope 1 × mass of isotope 1) + (% of isotope 2 x mass of isotope 2) / 100

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

mendeleev’s periodic table

A

-arranged by increasing atomic mass
-put similar properties below each other in groups
- left gaps for yet to be discovered elements
-looked at the chemical and physical properties of the elements next to a gap to predict the properties of these undiscovered elements

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

modern periodic table

A

-arranged by increasing atomic number
-rows = periods
-columns = groups (elements w similar
properties)
-metals on left side, non-metals on right

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

what is electron configuration?

A

the arrangement of electrons in an atom

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

how is electron configuration linked to an elements position on the periodic table?

A

-the number of shells is the period the element is in
-the number of electrons in the outermost shell is the group number of the element
-the number of electrons in all shells is the elements atomic number

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

why do elements in the same group have similar properties?

A

they have the same amount of electrons in their outer shell, when atoms collide & react, the outer shells interact, so because they have the same amount of electrons in their outermost shell, they have similar properties

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

valency

A

equal to the number of electrons that each atom needs to gain, lose or share to fill its outer shell

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

what is an ion?

A

an atom that has lost or gained electrons to obtain a full outer shell

38
Q

what is an ionic compound?

A

a compound that consists of positive and negative ions

39
Q

anion

A

negative ion

40
Q

cation

A

positive ion

41
Q

dot and cross diagram

A

a drawing to show only the arrangement of electrons of the atoms or bonding of a simple molecular structure

42
Q

ionic lattice

A

regular repeating arrangement of particles

43
Q

why is an ionic lattice formed?

A

the positive and negative ions attract one another and form a regular pattern with oppositely charged ions next to eachother

44
Q

why do solid ionic compounds form crystals?

A

the lattice arrangement continues in three dimensions

45
Q

what is an ionic lattice held together by?

A

ionic bonds

46
Q

what direction(s) do ionic bonds act in?

A

any direction

47
Q

naming ionic compounds

A

ide = 2 elements
ate = 3 or more with one oxygen

48
Q

why do ionic compounds have high melting and boiling points?

A

because of the strong electrostatic attraction between ions, it takes a lot of energy to overcome this attraction and break the many strong bonds to melt or boil the compounds

49
Q

why do ionic compounds conduct electricity only when molten or aqueous?

A

the ions are free to move and carry charge

50
Q

polyatomic ion

A

an ion made of two or more atoms

51
Q

covalent bonds

A

bonds created by sharing electrons with other atoms

52
Q

molecule

A

a group of atoms bonded together covalently

53
Q

what will molecules of the same element and compound always have?

A

a set size

54
Q

simple molecule

A

molecule made up of a small number of atoms held by covalent bonds

55
Q

why can’t atoms and molecules be seen with light microscopes?

A

they’re too small

56
Q

why do simple molecular substances have low melting and boiling points?

A

there are weak intermolecular forces between the molecules that do not require much energy to overcome

57
Q

why can’t simple molecular substances conduct electricity?

A

they have no charge

58
Q

what are giant covalent bonds?

A

many atoms joined by covalent bonds

59
Q

why do giant covalent bonds have a high melting and boiling points?

A

lots of energy needed to overcome strong bonds

60
Q

why aren’t giant covalent bonds electric conductors?

A

they have no charge

61
Q

why are giant covalent lattices insoluble?

A

the covalent bonds are far too strong to be broken by interaction with solvents (a substance can dissolve with water if it forms enough attractions with water molecules

62
Q

diamond (giant covalent lattice, form of carbon)

A

-each carbon atom joined to four other carbon atoms by covalent bonds
-no free electrons
-tetrahedral structure

63
Q

what are the properties of diamonds?

A

-diamonds are very hard due to the rigid structure of the carbon atoms held together by covalent bonds
-doesn’t conduct electricity
-high melting point

64
Q

what can diamonds be used for?

A

cutting tools

65
Q

graphite (giant covalent lattice, form of carbon)

A

-each carbon atom is joined to three other carbon atoms by covalent bonds
-hexagon layered network structure
-the layers have weak forces between them & can slide over one another
-each carbon atom has one un bonded outer electron which is delocalised

66
Q

properties of graphite

A

-can conduct electricity due to the delocalised electron
-slippery due to the weak forces

67
Q

uses of graphite

A

-lubricants
-pencils
-electrodes in batteries

68
Q

graphene (form of carbon)

A

structure resembles single layer of graphite

69
Q

properties of graphene

A

-high melting point & strong bc of regular arrangement of carbon atoms joined by covalent bonds
-conduct electricity well due to delocalised electrons

70
Q

fullerene (very large molecule)

A

a molecular form of carbon that consists of atoms arranged in the shape of a hollow sphere

71
Q

what are two fullerenes?

A

-nanotubes
-buckyballs

72
Q

nanotubes

A

resembles a layer of graphene, rolled into a tube shape

73
Q

properties of nanotubes

A

-high tensile strength, as in the tension that can be withstood without breaking
-conduct electricity due to delocalised electrons
-strong

74
Q

buckyballs

A

spheres or squashed spheres of carbon atoms

75
Q

properties of buckyballs

A

-slippery as there are weak intermolecular forces between buckyballs
-lower melting points than graphite or diamond

76
Q

metals properties

A

-shiny
-high melting points and densities,
-malleable (can be shaped without breaking)
-high density (high mass for its size)
-ductile (can be drawn into a long wire without snapping or breaking)
-good electric & heat conductors (delocalised atoms can move through the lattice structure & form an electric current)

77
Q

where are metals located on the periodic table?

A

left

78
Q

where are nonmetals located on the periodic table?

A

right side

79
Q

metal structure

A

positive ions in a sea of delocalised electrons

80
Q

non metal properties

A

-dull
-brittle (shatter when hit)
-poor electric & heat conductors
- low melting points

81
Q

relative formula mass

A

the sum of the relative atomic masses of the elements as given in the formula

82
Q

empirical formula

A

the simplest whole number ratio of atoms

83
Q

calculating empirical formula

A
  1. write out element symbols
  2. write out the mass/percentage of each element
  3. write Mr values
  4. divide masses by Mr
  5. divide by smallest number
  6. multiply (if needed) for integers
  7. write formula
84
Q

law of conservation of mass

A

atoms aren’t created or destroyed in a chemical reaction, they join together differently than before the reactions to form products, this means that the total mass stays the same

85
Q

reactions in a closed system

A

no substance enters or leaves, mass stays same

86
Q

reactions an non enclosed system

A

-substances can enter or leave
-if a gas escapes, the total mass will look as if it has decreased
-if a gas is gained, the total mass will look as if it has increased
-the total mass stays the same if the mass of the gas is included.

87
Q

concentration formula

A

mass of solute/volume of solvent

88
Q

concentration

A

how much solute is dissolved in a solvent

89
Q

mass formula (moles)

A

mass = mr x moles

90
Q

when does a reaction finish?

A

when one of the reactants is all used up

91
Q

what is a limiting factor in a reaction?

A

a reactant that is used up first in a chemical reaction

92
Q

what does the mass of the product formed in a reaction depend on?

A

the limiting reactant, this is because no more product can form when the limiting reactant is all used up

CHEMISTRY (9 decks)

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