Paper 1 - Atomic structure and the periodic table Flashcards
(88 cards)
1
Q
alkali metals
A
the elements in group 1 of the periodic table
2
Q
atom
A
the smallest part of an element that can exist . All substances are made up of atoms
3
Q
atomic nucleus
A
positively charged object composed of protons and neutrons at the centre of every atom with one or more electrons orbiting it
4
Q
atomic number
A
the number of protons in the nucleus
5
Q
Chromatography
A
A separation technique used to separate a mixture of chemicals by
distributing the components between two phases.
6
Q
Compound
A
A substance made up of two or more types of atoms chemically combined
together.
7
Q
Crystallisation
A
A separation technique used to produce solid crystals from a solution by
evaporating the solvent.
8
Q
Displacement:
A
: A chemical reaction in which a more reactive element displaces a less
reactive element from its compound.
9
Q
Electron
A
: Negatively charged subatomic particle which orbit the nucleus at various energy
levels. Very small relative mass (negligible).
10
Q
Electron shell
A
l: Different energy levels in atoms occupied by electrons.
11
Q
Element
A
A substance made up of only one type of atom.
12
Q
Filtration
A
A separation technique used to separate solids from liquids.
13
Q
Fractional distillation
A
A method of separating a mixture of substances according to their
different boiling points.
14
Q
Group (periodic table)
A
: The columns of the periodic table represent different groups of
elements. Elements with similar properties are in the same group.
15
Q
Halogens:
A
The elements in Group 7 of the periodic table.
16
Q
Ion
A
: An atom or molecule with an electric charge due to the loss or gain of electrons.
17
Q
Isotope:
A
Atoms of the same element with the same number of protons but a different number
of neutrons
18
Q
Mass number
A
The total number of protons and neutrons in the nucleus.
19
Q
Metals:
A
Elements that react to form positive ions. Found to the left and towards the bottom of
the periodic table.
20
Q
Mixture
A
A mixture consists of two or more elements or compounds not chemically combined
together.
21
Q
Neutron
A
Neutral subatomic particle present in the nucleus of the atom. Relative mass of 1.
22
Q
Noble gases
A
The elements in Group 0 of the periodic table.
23
Q
Non-metals:
A
Elements that react to form negative ions. Found towards the right and top of
the periodic table
24
Q
Nuclear model
A
The nuclear atomic model stated that the mass was concentrated at the
centre of the atom and that the nucleus was charged.
25
Periodic table
Table of elements arranged in order of atomic number and such that
elements with similar properties are in the same column (group).
26
Plum pudding model:
Atomic model devised after the discovery of the electron. The model
suggests the atom is a ball of positive charge with negative electrons scattered through it.
27
Proton
Positively charged subatomic particle present in the nucleus of the atom. Relative
mass of 1.
28
Relative atomic mass
An average value that takes account of the abundance of the
isotopes of the element.
29
Simple distillation
A procedure by which two liquids with different boiling points can be
separated.
30
Transition metals:
The collection of metallic elements in the middle of the periodic table.
31
how are the element listed and approximately how many are there
they are listed in the periodic table ; there are approximately 100
32
elements are classifies into two groups based on their properties ; what are these groups
metals and non- metals
33
elements ma combine through chemical reaction to form new products ; what are these new substances called
compounds
34
do compounds have the same properties as their constituent element
no they have different properties
35
what is a mixture ? does it have the same chemical properties as its consistuent materials
a mixture consists of two or more elements or compounds not chemically combined together ; it does have the same chemical properties
36
what are the 5 methods through which mixtures can be separated ? do these involve chemical reactions
filtration , crystallisation , simple distillation , fractional distillation and chromatography ; they do not involve chemical reactions
37
describe and explain simple distillation
simple distillation is used to separate liquid from a solution - the liquid boils off and condenses in the condenser . The thermometer will read the boiling point of the pure liquid . Contrary to evaporation , we get to keep the liquid.
38
describe and explain crystallisation / evaporation
evaporation is technique for separation of a solid dissolves in a solvent from a solvent
The solution is heated until all the solvent evaporates ; the solid stays in the vessel
crystallisation is similar , but we only remove some of the solvent by evaporation to form a saturated solution (the one where no more solid can be dissolved) .Then we cool down the solution , As we do it , the solid starts to crystallise , as it becomes less soluble at lower temperatures .The crystals can be collected and separated from the solvent via filtration
39
describe and explain fractional distillation
Fractional distillation is a technique for separation of a mixture of liquids . It works when liquids have different boiling points . The apparatus is similar to the one of simple distillation apparatus , with the additional fractionating column placed on top of the heated flask .The fractionating column contains glass beads .It helps separate the compounds .In industry mixtures are repeatedly condensed and vaporised. The column is hot at the bottom and cold at the top .The liquid will condense at different heights of the column
40
describe and explain filtration
filtration is used to separate an insoluble solid is suspended in a liquid .The insoluble solid get caught in the filter paper , because the particles are too big to fit through the holes in the paper . The filtrate is the substance that comes through the filter paper . Apparatus : filter paper + funnel
41
describe and explain chromatography
chromatography is used to separate a mixture of substances dissolves in a solvent .In paper chromatography , we place a piece of paper with a spot containing a mixture in a beaker with some solvent. The solvent level will slowly start to rise , thus separating the spot into few spots
42
what is a separating funnel
a separatory funnel is an apparatus for separating immiscible liquids .Two immiscible liquids of different densities will form two distinct layers in the separatory funnel .We can run off the bottom layer to a separate vessel
43
describe the plum - pudding model
the atom is a ball of positive charge with negative electron embedded in it
44
describe the Bohr/nucleus and how it came about
the nuclear model suggests that electrons orbit the nucleus at specific distances (shells) - it came about from the alpha scattering experiments.
45
later experiments led to the discovery of smaller , positive particles in the nucleus ; what are these particles called
protons
46
what did the work of James Chadwick provide evidence for ?
the existence of neutrons in the nucleus
47
describe the structure of an atom
the atom has a small central nucleus ( made up of protons and neutrons ) around which there are electrons
48
state the relative masses and relative charges of the proton , neutron and electron
masses : 1, 1 , very small
charges : 1 , 0 , -1
49
explain why atoms are electrically neutral
They have the same number of electrons and protons
50
what is the radius of an atom
0.1nm(nanometre )
51
what name is given to the number of protons in the nucleus
atomic number
52
atoms of the same element have the same number of which particle in the nucleus
protons
53
where is the majority of mass of an atom
nucleus
54
what is the mass number
the total number of protons and neutrons
55
how does one calculate the number of neutrons using the mass number and atomic number
subtract the atomic number from the mas number
56
what is an isotope ?Do isotopes of a certain element have the same chemical properties?
atoms of the same element (same proton number ) that have a different number of neutrons
They have the same chemical properties as they have the same electronic structure
57
what is the relative atomic mass
the average mass value which takes the mass and abundance of isotopes of an element into account , on a scale where the mass of 12 carbon is 12.
58
give the electronic configurations of He(2) , Be(4) , F(9) , Na(11) and Ca(20) to demonstrate how shells are occupied by electrons
2
2 , 2
2, 7
2 , 8 , 1
2 , 8 , 8 , 2
59
compare the properties of metals and non-metals
Metals are good conductors of heat and electricity, while non-metals are not. Metals tend to lose electrons in chemical reactions, while non-metals tend to gain electrons. Metals tend to be lustrous, while non-metals tend not to be. Metals are malleable and ductile, while non-metals tend to be brittle
60
what is formed when a metal reacts with a non-metal?
an ionic compound (made of positive and negative ions)
61
what is non - metal reacts with a non-metal?
a molecular compound containing covalently bonded atoms . Atoms share electrons , as opposed to transferring electrons between each other (ionic compounds )
62
explain the following : solute , solvent , solution , miscible , immiscible , soluble , insoluble
a solute is a substance that is dissolved in a solvent . Together , they form a solution
Miscible refers to the substances that mix together eg. water and alcohol .Water and oil are immiscible i.e. they do not mix
Soluble refers to the substance that can be dissolves in a solvent , eg. salt in water .Insoluble substance won't dissolve in a particular solvent
63
the columns of the periodic table are called
groups
64
the rows of the periodic table are called
periods
65
are elements in the same group similar or different
they have similar chemical properties , as they have the same number of outer shell electrons
66
in terms of energy levels , what are the differences between elements of the same period
They have the same number of energy levels
67
electrons occupy particular energy levels , with each electron in an atom at a particular energy level ; which available energy level do electrons occupy ?
the lowest available energy level
68
the elements of group 0 are commonly known as ..?
the noble gases
69
what makes the periodic table periodic ?
similar properties occur at regular intervals
70
elements in the same group have the same number of electrons in their outer shell ; what does this tell us about their chemical properties ?
they have similar chemical properties
71
in terms of shells , what is the difference between elements in the same period
they have the same number of shells
72
what change in shell number is seen as one moves down a group ?
the number of shells increases
73
early periodic tables were incomplete and elements were placed in inappropriate groups if what was to be followed
the strict order of atomic weights
74
knowledge of what made it possible to explain why the order based on atomic weights was not always correct ?
isotopes
75
Mendeleev overcame some problems with the table by doing what ?He also changed the order of some elements based on what ?
leaving gaps ; atomic weights
76
the majority of elements are
metals
77
elements that react to form positive ions are
metals
78
elements that do not form positive ions are
non-metals
79
elements in group 1 are known as
the alkali metals
80
state three characteristics of the alkali metals
all have one electron in their outer shell ; have low density ; are stored under oil (to prevent reactions with oxygen or water ; are soft(can be cut with knife)
81
how do group 1 elements react with non-metals?why are these reactions similar for the different group 1 elements ?
they form ionic compounds which are soluble white solids which form colourless solution - they have one electron in their outer shell
82
how do group 1 elements react with wate r?
they release hydrogen ad form hydroxides which dissolves to form alkaline solutions ; react vigorously with water fizzing and moving around on the surface of the water .
83
how does reactivity change moving down group 1 ? why?
reactivity increases as the atoms get larger and the distance between the nucleus and the outer electrons increases and thus attraction from the nucleus decreases , allowing them to more easily lose electrons .
84
state 5 characteristics of group 7
1) 7 electrons in outer shell
2) coloured vapours
3)diatomic molecules
4)form ionic salts with metals
5) form molecular compounds with non - metals
85
State 4 group 7 elements and states of matter of molecules the form
1) Fluorine , F . F2 , is a pale yellow gas
2) Chlorine , Cl . Cl2 is a pale green gas
3) Bromine , Br . Br2 is a dark brown liquid
4) Iodine , I , I2 , is a grey solid
86
state 3 changes that occur in group 7 as one moves down the group
1) higher relative molecular mass
2) higher melting and boiling point
3) less reactive - less easily gain electrons
87
compare group 1 metals with transition metals
group 1 metals and transition metals are heat and electricity conductors .They are shiny when polished and form ionic compounds with non-metals
Transition metals have higher densities and higher melting points than group 1 metals .They are less reactive and harder than group 1 metals
88
what is a catalyst
a catalyst is a chemical substance that increases the rate of a chemical reaction.
