Atoms, Elements and Compounds and The Particulate Nature of Matter Flashcards
Name the states of matter (3)
solids
liquids
gases
State symbol of solid
s
State symbol of liquid
l
State symbol of gas
g
Define a particle
simplest and smallest unit of matter
Define atoms
simplest particles that make up everything
Define compounds
two or more types of atoms chemically joined together
Define a property
characteristic of something
Which state of matter has a fixed shape
solid
Which state of matter has a fixed volume (2)
solid
liquid
Which state of matter flows (2)
liquid
gas
Particle arrangement of solid (3)
packed tightly together
has strong forces of attraction holding particles together
particles only vibrate on the spot
Particle arrangement of liquid (4)
packed tightly together
particles have strong forces of attraction
particles can move over one another
liquids take shape of their container
Particle arrangement of gas (3)
spaced far apart
particles move about freely
spread to fill container they are in
Which states cannot be compressed and why (3)
solids
liquids
particles already packed together
Which state can be compressed and why (2)
gas
particles are spread out
Define melting point
temperature of substance when it changes from solid to liquid
Define boiling point
temperature of substance when it changes from liquid to a gas
Process of change from solid to liquid
melting
Process of change from liquid to gas
boiling
Process of change from gas to liquid
condensing
Process of change from liquid to solid
freezing
How process of evaporation works (4)
liquid particles have some particles which move faster
faster particles have more kinetic energy
hence they have enough energy to escape liquid surface as gas
not all particles evaporate as boiling point not reached
Define molecules
particles of atoms joined together by covalent bonds
Define an ion
charged particles formed by atom gaining or losing electron
Define diffusion (2)
movement of particles through a liquid or gas
movement of particles from an area of high concentration to an area of low concentration
Determinants of rate of diffusion (2)
molecular mass - larger molecular mass is slower
vacuum - faster as no other particles to collide with
Define a chemical reaction (2)
reaction which occurs when 2 or more substances react to form a new substance
difficult to reverse/irreversible
Define a physical change (3)
involve a change of state
no new substance is made
easily reversible
Name indicators of chemical reaction (4)
colour change
gas produced
solid formed
temperature change
Name reversible reactions (2)
Hydrated copper(II) sulfate crystals <-> Anhydrous copper(II) sulfate + Water
Hydrated cobalt(II) chloride <-> Anhydrous cobalt(II) chloride + Water
Colour change from hydrated copper sulfate crystals to anhydrous copper sulfate
blue crystals to white powder
Colour change from hydrated cobalt chloride crystals to anhydrous cobalt chloride
pink crystals to blue
Define an element
a substance which contains only one type of atom
Word equation of Hydrated copper(II) sulfate crystals <-> Anhydrous copper(II) sulfate + Water
CuSO4 5H2O(s) -> CuSO4(s) + 5H2O(l)
Chemical equation of Hydrated cobalt(II) chloride <-> Anhydrous cobalt(II) chloride + Water
CoCl2 6H2O(s) -> CoCl2(s) + 6H2O(l)
Define mixture
contains elements and compounds not chemically joined together
Properties of metals (7)
shiny/lustrous
good conductors (heat and electricity)
high melting and boiling points
high tensile strength
sonorous (rings when struck)
ductile (can be stretched into wire)
malleable (can be beaten into shape)
Properties of non-metals (4)
dull
poor conductors (heat and electricity)
low melting and boiling points
brittle (breaks easily)
Exceptions to metal and non-metal properties (4)
carbon and silicon have high melting points
carbon in form of graphite conducts electricity
mercury has low melting point
alkali metals are soft, have low melting points, not sonorous
Define metalloids
elements that exhibit characters of both non-metals and metals
Define alloys
substances formed when metals mix with other elements
Examples of alloys (3)
steel
bronze
brass
Define a solution
mixture formed when one substance dissolves fully into another
Define solute
substance that is dissolved
Define solvent
substance which does the dissolving
Define concentration of a solution (2)
amount of solute dissolved in certain volume
can be expressed as number of moles of solute in one decimetre cubed of solution
What 3 sub-atomic particles are in an atom (3)
proton
neutron
electron
Name of centre of atom
nucleus
Features of protons (3)
found in nucleus
have a positive charge (+1)
have relative mass of 1 atomic mass unit (amu)
Features of electrons (3)
found in electron shells orbiting nucleus
have negative charge (-1)
have relative mass of 1/2000
Features of neutrons (3)
found in nucleus of atom
have no charge and are neutral (0)
have relative mass of 1 amu
What is the charge of atoms (2)
atoms have no charge (neutral)
number of protons equal to number of electrons
What does nuclide notation show (3)
element symbol
proton/atomic number
nucleon (mass) number
What does proton/atomic number show
number of protons an atom has
What happens to proton/atomic number when you move from left to right across a period
proton/atomic number increases
Define periodicity
trend that can be seen in periodic table
What does nucleon/mass number show
number of protons and neutrons an atom has
What is most of an atom
empty space
How are electrons arranged (4)
arranged in shells
first shell holds 2 electrons
2nd shell holds 8 electrons
3rd shell holds 8 electrons
Features of noble gases (2)
full outer electron shell
are stable as electron shell full
Name of outer electrons
valence electrons
What do elements in the same group have and why (2)
similar chemical properties
due to same number of valence electrons
What happens to the number of electrons as we move along a period
number of electrons in outer shell increases
Define an isotope
atoms of same element with same atomic number but different mass number due to different neutron number
Properties of Isotopes
have same chemical properties as they have same number of valence electrons
What is the charge of an atom which has lost electrons
positive charge
Which atoms tend to lose electrons
metals
What is the charge of an atom which has gained electrons
negative charge
Define cations
positive ions
Define anions
negative ions
Which substances will an ionic bond form between (2)
metal
non-metal
How do ions form (3)
metal atoms give electrons to non-metal atoms
both atoms are stable charged particles
atoms attracted as they are oppositely charged
Define an ionic bond
electrostatic force of attraction between oppositely charged ions
Name given to pattern which ionic compounds are organised in
ionic lattice
Ionic lattice structure
ion surrounded by ions of opposite charge
Define oxidation
when an atom/ion loses electrons
Define reduction
when an atom/ion gains electrons
Define electricity
flow of charged particles (ions or electrons)
In metals and graphite which part of the atom moves and carries an electric current
outer electrons of atoms (delocalised electrons) which can move and carry current
Define an electrolyte
molten substance or solution that conducts
At which states do metals conduct (2)
solid
liquid
Can non-metals and covalent substances (except graphite) conduct electricity
no
Features of ionic substances (5)
hard crystals - strong attraction between positive and negative ions
high melting points - lot of energy needed to overcome forces of attraction between ions
dissolves in water - water forms electrostatic attractions with ions and “pluck” them off lattice
does not conduct when solid - electrons held tightly in lattice and cannot move
conducts when molten/solution - lattice breaks and ions free to move
What determines strength of ionic bond
greater charge greater strength
When will a covalent bond form with
non-metals
Define a covalent bond
pair of electrons shared by two atoms
Define a diatomic molecule
molecule made up of 2 atoms bonded together
Define triatomic molecule
molecule made up of 3 atoms bonded together
Example of triatomic molecule
H2O
Define valency
number of bonds an element needs to form
Group 1 valency
1
Group 2 valency
2
Group 3 valency
3
Group 4 valency
4
Group 5 valency
3
Group 6 valency
2
Group 7 valency
1
Group 8 valency
0
How is a covalent bond held together (3)
positively charged protons in the nucleus
negatively charged electrons in shared area
electrons and protons attracted as opposites attract
Define macromolecules
molecules that contain large number of atoms
Define allotropes
different forms of same element
2 giant covalent structures of carbon
diamond
graphite
Diamond structure (3)
carbon atoms arranged in tetrahedral structure
carbon bonded to 4 other carbon atoms
held together by strong covalent bonds
Graphite structure (3)
carbon atoms in hexagonal shape in layers
each carbon atom bonds to 3 other carbon atoms
layers held together by weak intermolecular forces of attraction
Properties of diamond (3)
strong covalent bonds
high melting point - lots of energy needed to break strong bonds between atoms
hard substance
Properties of graphite (4)
strong bonds between atoms
weak intermolecular forces between layers
weak IMFs cause layers to slide over each other
is flaky and can be used as lubricant
Can diamond conduct electricity
no
Can graphite conduct electricity
yes
Why is graphite able to conduct electricity (2)
has delocalised electrons (electron left from not having 4th bond)
electron is free to move and allows conduction
Examples of macromolecules (3)
silicon (IV) oxide
diamond
graphite
Number of covalent bonds for silicon (IV) oxide
4
Melting and boiling point of covalent bonds
low melting and boiling points
Why do covalent bonds have low melting and boiling points (2)
covalent bonds (intramolecular forces) not broken when substance melted or boiled
much weaker forces of attraction (intermolecular forces) broken
Define volatility
how easily substances vaporise
What are covalent bonds said to be
volatile since they have low melting and boiling points
Do covalent substances conduct electricity why? (3)
do not conduct electricity as no free electrons to carry charge
do not have ions
exceptions - some covalent substances will form ions when dissolved in water
Are covalent substances insoluble or soluble in water
insoluble
Melting and boiling points of giant covalent structures
high melting and boiling points
Structure of giant covalent structures (2)
have strong covalent bonds - no weak
Why do giant covalent bonds have high melting and boiling points (2)
every strong covalent bond must be broken
hence require lots of energy
