1
Q
What are physical properties?
A
Characteristics that can be observed or measured.
2
Q
What are the physical properties of metals?
A
1) appearance: shiny
2) mpt & bpt: high
3) state at room T: solid
4) malleable when solid
5) dutile when solid
6) good elec. & thermal conductors
3
Q
What are physical properties of non-metal elements?
A
1) appearance: dull
2) mpts & bpts: usually low
3) state at room T: ~1/2 solid, ~1/2 gas
4) brittle when solid
5) non-ductile when solid
6) poor conductors (are insulators)
4
Q
What does malleable mean?
A
Something can bend w/out shattering.
5
Q
What does brittle mean?
A
Something shatters when hammered.
6
Q
What does ductile mean?
A
Something can be pulled into wires.
7
Q
What are the 2 ways of numbering groups in the Periodic Table?
A
1) older system from 1 to 0
2) newer IUPAC system from 1 to 18
8
Q
What does IUPAC stand for?
A
International Union of Pure and Applied Chemistry.
9
Q
Which elements are metals?
A
Everything left of the ‘staircase’ going from aluminium to polonium & livermorium, except for hydrogen.
10
Q
Which elements are non-metals?
A
Everything right of the ‘staircase’ going from boron to astatine as well as hydrogen.
11
Q
Which elements are solids, liquids, and gases at room temperature?
A
1) liquid: mercury & bromine
2) gas: hydrogen, nitrogen, oxygen, fluorine, chlorine & all of Group 0
3) solid: everything else
12
Q
What is the Periodic Table?
A
A table in which all the elements are arranged in rows & columns in order of increasing atomic no.
13
Q
What are features of the boundary in the Periodic Table?
A
1) metal elements are placed L of it
2) non-metal elements are placed R of it
3) elements on it have properties of both metals & non-metals
14
Q
What is a chemical property?
A
A characteristic of a substance that can only be determined by studying its chemical reactions.
15
Q
What are the chemical properties of metals?
A
1) lose e^-s to form +ve ions
2) don’t react w/ each other (form alloys)
3) may react w/ oxygen to prod. oxides
-> when dissolved in water, metal oxides prod. alkaline solutions
16
Q
What are the chemical properties of non-metals?
A
1) non-metals gain e^-s to form -ve ions
2) non-metals react w/ each other to prod. compounds that consist of molecules
3) may react w/ oxygen to prod. oxides
-> when dissolved in water, non-metal oxides prod. acidic solutions
17
Q
True or False?: metal and non-metal oxides have different properties.
A
True, e.g.:
a) metal oxides prod. alkaline solutions if they dissolve in water
b) non-metal oxides prod. acidic solutions if they dissolve in water
18
Q
What is a period in the Periodic Table?
A
A horizontal row.
19
Q
What is a group in the Periodic Table?
A
A vertical column.
20
Q
How are periods ordered?
A
Atomic no. increases by 1 going from 1 element to the next.
-> means no. e^-s in each atom should also increase by 1 each time
21
Q
What do the elements of a group all have and why?
A
Similar chem. properties due to the arrangement of their e^-s.
22
Q
How are electrons arranged in atoms?
A
1) around nucleus in shells
2) there are max no.s e^-s in each shell
a) 1st: 2
b) 2nd: 8
c) 3rd: 8
d) 4th: 18
23
Q
What does the electronic structure of an element show?
A
How the e^-s are arranged in its atoms.
24
Q
What is the outer shell?
A
The outermost occupied shell.
25
How do you find the electronic structure of an atom?
1) fill each of shells in turn beginning w/ 1st
2) write electron structure of atom
-> a.b (dot shows you're going from 1 shell to next)
26
How can you work out electronic structures?
Counting from hydrogen period by period until you reach the element you want (you ignore the transition metals for this / only 'old' ordered Groups, so not only IUPAC(?)).
27
How is electronic structure related to the Periodic Table?
Position:
a) last no. = non-IUPAC group no.
-> but Group 0 elements have full outer shells
b) no. no.s = period no.
c) sum of no.s = atomic no.
28
What is an ion?
An electrically sharged particle formed when an atom or group of atoms loses or gains e^-s.
29
What type of ions do metals form and how?
Metal atoms lose e^-s to form +ve ions.
30
What type of ions do non-metals form and how?
Non-metal atoms gain e^-s to form -ve ions.
31
Do the numbers of protons and neutrons change when an atom forms an ion?
No.
32
Can you see individual ions?
No.
33
How are ions formed?
Atoms losing outer electrons / gaining electrons to complete outer shells.
34
How do you work out the charges for most simple ions?
Use non-IUPAC group no. or original metal atom.
35
How do you work out the charges for most simple negative ions?
8 - group no. of original non-metal atom
36
How can you work out the electronic structures of ions?
1) electron structure of original atom
2) how many e^-s lost or gained
-> should have complete outer shell
37
What is an electron diagram?
A diagram which represents the electronic strcuture of an atom or ion.
38
How do you draw electron diagrams?
1) draw circle to rep each shell
2) draw dots or crosses to rep e^-s of atom or ion
3) ions go inside brackets w/ charge written at top right
4) element's symbol can be written at centre instead of showing a nucleus
5) electrons all the same in these diagrams
-> use of dots or crosses lets you model which atom provided esp. e^-
39
How do ionic compounds form?
When metal reacts w/ non-metal, e^-s transferred from metal atoms to non-metal atoms so both achieve > stable electron structures.
a) metal atoms become +ve ions
b) non-metal atoms become -ve ions
40
How can you mo
41
How can you model the ions in the ionic compound that's formed?
Dot-and-cross diagram.
-> show e^-s from 1 atom as dots & e^-s from other as crosses
42
What is the structure and bonding in ionic compounds?
1) in (s) state contain +ve & -ve ions arranged in regular way
-> arrangement called giant ionic lattice
2) ions held in place by ionic bonds which act in all directions
-> strong electrostatic forces of attraction between opp. charged ions
43
What are ionic bonds?
Electrostatic forces of attraction between oppositely charged ions.
44
What does giant ionic lattice mean?
1) 'giant' - arrangement is repeated
2) 'ionic' - structure has ions
3) 'lattice' - arrangement regular not random
45
How do ionic bonds act?
In all directions.
46
What can space-filling models be used for?
Representing ionic compounds.
47
What is the problem with drawing a model of a giant ionic lattice?
It exists in 3D but can only draw it in 2D.
48
What is a ball-and-stick model?
A model where:
1) each plastic ball rep.s ion
2) each plastic link rep.s ionic bond
49
What are advantages of giant ionic lattices?
1) give you clearer idea of structure & shape of lattice
50
What are limitations of giant ionic lattices as models?
1) ions are close together (not acc. rep of distance between ions (?))
2) bonds are forces not physical objects made from matter
51
What is a covalent bond?
A shared pair of electrons.
52
How do covalent bonds form?
Between 2 non-metal atoms when the atoms get close enough to share e^-s in their outer shells.
-> by sharing e^-s, atoms complete outer shells
53
Why do atoms share electrons?
Complete outer shells.
54
How do non-metal atoms complete outer shells?
Sharing electrons.
55
How can covalent bonds be modelled?
Using dot-and-cross diagrams:
1) e^-s from 1 of bonded atoms shown as dots
2) e^-s from other shown as crosses
3) each pair of e^-s in shared area between overlappping circles rep.s covalent bond
4) only outer shells usually shown
56
What is a molecule?
A particle in which non-metal atoms are joined together by covalent bonds.
57
What is a simple molecule?
A molecule (a particle in which non-metal atoms are joined to each other by covalent bonds) that only contains a few atoms.
58
How can (simple) molecules be modelled?
Using dot-and-cross diagrams.
59
What do hydrogen, oxygen, water & carbon dioxide all exist as?
Simple molecules.
60
How many covalent bonds does hydrogen form?
Only 1.
61
How can you calculate the number of bonds that non-metals (except for hydrogen) form?
8 - non-IUPAC group no.
62
What does inert mean?
Unreactive.
63
Why do Group 0 (IUPAC 18) elements not form bonds?
They are unreactive (inert).
64
What is the structure and bonding in simple molecules like?
1) covalent bonds involve electrostatic forces of attraction js like ionic bonds
-> however forces are between nucleus of each bonded atom & shared e^-s
2) covalent bonds between atoms in simple molecule = strong
3) -> but IMF between molecules = weak
65
What are possible models for simple molecules?
1) space-filling model
2) ball-and-stick
3) displayed formula
66
What are the limitations of ball-and-stick models?
1) both sizes of atoms & length of bonds exaggerated
2) suggests e^-s that make the bonds don't move
67
What is a displayed formula?
A model (for simple molecules) where each atom is represented by its chem symbol & each covalent bond by straight line.
68
What is a positive about displayed formulae?
Simple molecules have shapes.
69
What are limitations of simple molecules?
Doesn't show the 3D shape of the molecule.
70
What are giant covalent structures?
A structure consisting of v. many non-metal atoms joined by covalent bonds & arranged in a repeating regular pattern called a giant lattice.
-> these structures also called giant covalent lattices
71
Explain features of diamond.
1) form of carbon
2) exists as giant covalent structure in which each C atom joined to 4 others by covalent bonds (strong covalent bonds)
72
What are the chemical formulae of giant molecules?
Like in ionic compounds where v. many ions involved, have v. many atoms so instead empirical formula for substance used.
-> why diamond has formula of C in chem equations
73
Explain the empirical formulae of giant covalent structures (silica).
1) each silicon atom covalently bonded to 4 oxygen atoms
-> would give empirical formula SiO4
2) but each oxygen atom also bonded to 2 silicon atoms
-> would give empirical formula Si2O
3) taken over whole structure each silicon atom is on avrg bonded to 2 oxygen atoms
74
What is the formula for buckminsterfullerene?
C60, not C.
75
What are the atoms in silica joined in?
Giant covalent structure.
76
What are polymers made from?
All (artificial & natural) made from many smaller molecules called monomers.
-> these monomers able to join end to end in chem. reactions prod.ing longer polymer molecules
77
How is poly(ethene) / polythene made?
Many ethene molecules joining end to end.
78
How is protein made?
Many amino acid molecules joining end to end.
79
What is keratin (in hair) an example of?
A natural polymer, a protein.
80
What is a simple model for how polymers form?
monomers -> polymers
0 0 0 -> 0-0-0
abc -> poly(abc)
81
What are monomers?
Simple molecules.
82
What do monomers consist of?
A few non-metal atoms joined to each other by covalent bonds.
83
How can you usually model monomers?
Using:
1) dot-and-cross diagrams
2) space-filling models
3) ball-and-stick models
84
Why are polymers not usually modelled by dot-and-cross diagrams, space-filling models or ball-and-stick models?
Would be v. diff.
85
How are polymer molecules modelled?
1) each polymer molecule drawn as wavy line
2) -> sometimes have straight lines between them to rep covalent bonds between individual polymer molecules
3) are weak IMF between polymer molecules but not shown
86
What is cross linking?
How (polymer) chains are joined together by strong covalent bonds.
87
True or False?: all polymers are made from 1 type of monomer.
False, some polymers are made from several diff. types of monomer, like proteins & DNA.
88
How can polymers made from 1 type of monomer be modelled?
Using the idea of a repeating unit:
-> section of polymer molecule repeated over & over like links on chain
89
How would you represent the monomers of ethene its repeating unit / poly(ethene)?
ethene: n(H H)
I I
C=C
I I
H H )
poly(ethene):
(H H
I I
-C-C-
I I
H H)n
90
True or False: all metals are solid at room temperature.
False, mercury isn't.
91
What is the structure of metals like?
1) all except mercury are (s) at room T
2) atoms packed together in regular way forming giant metallic lattice
-> modelled by drawing circles or spheres arranged in regular pattern touching each other
92
What are metallic bonds like?
1) like in their reactions w/ non-metals, metal atoms lose e^-s from their outer shell to form +ve ions
a) e^-s leave outer shells of the metal atoms forming 'sea' of delocalised e^-s around +ve ions
-> e^-s free to move thru structure so called delocalised e^-s
2) metallic bonds: strong electrostatic forces of attraction between delocalised e^-s & closely packed +vely charged metal ions
93
What are delocalised electrons?
Electrons free to move thru the structure of a metal.
94
What are metallic bonds?
The strong electrostatic forces of attraction between the delocalised electrons & closely packed +vely charged metal ions.
95
What does 'localised' mean?
Restricted to esp. place.
96
What does 'delocalised' mean?
Free to move from usual place.
97
What must you do when describing (most) bonds?
Explain clearly which objects being attracted to each other in bond (bc all electrostatic forces of attraction).
98
Explain features of a metallic structure.
Extends in 3Ds.
Metallic bonding extends in allDs.
99
What are limitations of an isometric diagram and elevation view of metals (2D models of metals)?
You lose ~ info when you rep structure & bonding in 2D bc metallic structure extends in 3D & its metallic bonding in allD.
100
True or false?: Mendeleev was the chemist who made the 1st attempt to organise the elements into a table.
False, but it was the most successful and led to our modern Periodic Table.
101
What evidence did Mendeleev consider when organising the elements into a table?
His own & other scientists' evidence abt elements for several yrs before his 1st table, including:
a) atomic weights of known elements, similar to our modern relative atomic masses
b) knowledge of chem. reactions of diff. elements
c) knowledge of physical properties like mpts & bpts
102
What did Mendeleev do?
1) arranged all elements known at time in order of increasing atomic weight
2) grouped elements w/ similar chem properties
-> but swapped positions of tellurium & iodine bc felt this matched their chem properties better
3) left spaces for elements he thought would exist but weren't yet discovered & predicted their properties from those of nearby elements
103
What did Mendeleev do after making his first table?
1) his 1st Periodic Table showed groups as rows, not columns
2) 1871: rotated table so groups were in columns as in modern PT
3) 3 of his predicted elements were discovered between 1876 & 1886
-> found to have similar properties to 1s he'd predicted yrs before
104
Why is the modern Periodic Table in order of atomic number?
1) Mendeleev dev.d his table w/out knowing abt atomic structure
2) during his lfe, atomic no. element was js position in PT
3) Mendeleev died in 1907 pre proton discovered
4) 1913: Henry Moseley, Eng. Physicist disoc'd atom's atomic no. acc. no. protons in nucleus
5) Moseley's work showed 7 gaps left to fill in 1913 PT
-> also explained why Mendeleev had been right to swap tellurium & iodine around (as is in modern PT)
105
How was Group 0 discovered?
1) 1894: Lord Rayleigh & William Ramsay discovered argon
-> no 1 not even Mendeleev had predicted its existence
2) 1895: helium discovered by Ramsay
-> Mendeleev thought elements should be able to react w/ other elements so was reluctant to believe helium & argon elements
3) 1898: Ramsay discovered 3 > new elements
-> Mendeleev hasn't predicted existence of neon, krypton or xenon either
-> all 3 v. unreactive gases
4) Ramsay believed 5 gases he'd discovered formed new group of elements & suggested to M should be placed next to Group 7 in PT
-> accepted by Mendeleev gases rlly were elements & should be placed there
106
What are the patterns of chemical properties?
To understand patterns of chem properties in PT, remember:
1) elements arranged in order of increasing atomic no.
2) atomic no. = no. protons in atom
3) no. e^-s in atom = no. protons
4) electronic structure determined by no. e^-s
5) electronic structure of element determines its chem properties
-> means there's link between position of element in PT & its chem properties
107
How does reactivity change in Group 1?
Increases down group 1.
108
How does reactivity change in Group 2?
Increases as you go down.
109
How does reactivity change in Group 7?
Decreases as you go down.
110
What is the reactivity of Group 1, 2, 7 & 0 like?
1) v. reactive
2) reactive
3) v. reactive
4) v. unreactive
Chemistry OCR
flashcards
Decks in class (18)
# Cards
-
C2.1 Purity and Separating Mixtures94
-
C2.2 Bonding110
-
C2.3 Properties of Materials48
-
C3.1 Introducing Chemical Reactions54
-
C3.2 Energetics29
-
C3.3 Types of Chemical Reactions62
-
C3.4 Electrolysis46
-
C4.1 Predicting Chemical Reactions60
-
C4.2 Identifying the Products of Chemical Reactions27
-
C5.1 Monitoring Chemical Reactions58
-
C5.2 Controlling Reactions57
-
C5.3 Equilibria29
-
C6.1 Improving Processes and Products180
-
C6.2 Organic Chemistry62
-
C6.3 Interpreting and interacting with Earth Systems22
-
C1.1 The Particle Model42
-
C1.2 Atomic Structure49
-
C7 Practical Skills81
