Chemistry SLOPS Flashcards
define atom
The smallest part of an element that can still be recognised as that element
define element
a substance made of only one type of atom
define compound
a substance made of two or more different atoms chemically bonded together
what does soluble mean?
dissolves in water
what does insoluble mean?
does not dissolve in water
describe the plum pudding model
ball of positive charge with electrons embedded in it
which scientist developed the plum pudding model
JJ Thomson
which discovery did the alpha particle scattering experiment lead to?
that atoms have dense nucleuses with a positive charge
what did Bohr propose about electrons
electrons orbit at set energy levels
which scientist provided evidence for neutrons in the nucleus
James Chadwick
3 subatomic particles
protons
neutrons
electrons
masses of subatomic particles
protons: 1
neutrons: 1
electrons: very small
the relative charges of the subatomic particles
protons: +1
neutrons: 0
electrons: -1
how are the subatomic particles arranged in an atom
protons and neutrons in the nucleus
electrons orbiting in shells
what is an isotope
atoms of the same element with a different number of neutrons
what is the overall charge of an atom neutral
there are the same number of protons as electrons
the overall charge of the nucleus
positive
only made up of protons and neutrons
what is the atomic number of an atom
the number of protons in an atom
what is the mass number of an atom
the number of protons and neutrons
the name of group 1
the alkali metals
the name of group 7
the halogens
the name of group 0
the noble gases
the trend in reactivity down group 1
increases down
the trend in reactivity down group 7
decreases down
how is the periodic table organised
atomic number and groups of elements with similar chemical properties
how was the old periodic table organised
by atomic weight
name the scientist who developed the modern periodic table
Mendeleev
what did Mendeleev do for undiscovered elements
he left gaps
what can the group number tell you about the electrons in an atom?
how many electrons in the outer shell
what are periods in the periodic table
the rows in the periodic table
what charge do electrons have
negative
why did Mendeleev leave gaps in his periodic table
for elements that had not been discovered yet
why did Mendeleev put some elements in groups
because they had similar chemical properties
why is group 0 highly unreactive
the have a stable arrangement of electrons
(full outer shell)
sodium + water ➡️
sodium hydroxide + hydrogen
sodium + chlorine ➡️
sodium chloride
sodium + oxygen ➡️
sodium oxide
the trend in boiling point down group 7
increases down the group
potassium bromide + chlorine ➡️
potassium chloride + bromine
what type of reaction is this?
potassium bromide + chlorine ➡️ potassium chloride + bromine
displacement reaction
how do you calculate the number of neutrons in an atom
mass number - atomic number
what is an ion
an atom which has lost or gained electrons
how many electrons can go in the first shell
2
how many electrons can go in the 2 and 3 shell
8
what is the definition of a displacement reaction
a more reactive element will displace a less reactive element from a compound
are halogens metals or non metals
non metal
what colour flame is produced when potassium reacts with water
lilac
group 7 are diatomic
what does this mean
they exist in molecules made up of pairs of atoms
the colour and state of chlorine at room temperature
green gas
the colour and state of iodine at room temperature
grey solid
what happens to the number of electron shells down the group
increase in the number of shells
state the charge of all elements in group 1 when they become ions
+1
state the charge of all the elements in group 7 when they become ions
-1
explain why group 1 gets more reactive down the group
atoms get bigger down the group
electrons are further away from the nucleus
lose an electron more easily
explain why group 7 gets less reactive down the group
more shielding down the group
atoms get bigger down the group
electron further away from the nucleus
electron is gained less easily
state the observation of sodium with water
fizzes
melts
floats
moves around the surface
disappears
describe the structure of a giant ionic lattice
strong electrostatic forces of attraction between oppositely charged ions acting in all directions
state the general melting/boiling points of ionic substances
high melting and boiling points
why do ionic substances have high melting points
large amounts of energy needed to break the many strong bonds
when can ionic compounds conduct electricity
when they are molten or dissolved
because the ions will be free to move
state the type of bonding between non metals
covalent
describe covalent bonding in terms of electrons
sharing of electrons
do small covalent substances have high or low boiling points
low boiling points
why do small molecules have low melting points
the weak intermolecular forces are easily overcome by a small amount of energy
state the trend in intermolecular forces as molecules get bigger
as the molecule gets bigger, the intermolecular forces get stronger
do small covalent molecules conduct electricity
no
state the type of bonding in metals
metallic bonding
describe the metallic bonding structure
strong electrostatic forces of attraction between positive ions and delocalised electrons
state the general melting point of metals
high melting point
four properties of metals
malleable
ductile
good conductors of heat and electricity
high melting points
why are metals good conductors of thermal energy
energy is transferred by delocalised electrons
what is an alloy
a mixture containing at least one metal
describe why alloys are harder than pure metals
layers of atoms are distorted so layers cannot easily slide over eachother
why are metals good conductors of electricity
delocalised electrons carry a charge and flow through the metal
state the element, diamond, graphite and fullerenes are made from
carbon
state the type of bonding between carbon atoms
covalent
how many bonds does each carbon have in a diamond
4
state 4 properties of diamond
very hard
high melting point
does not conduct electricity
insoluble
how many bonds does each carbon have in graphite
3
why is graphene soft
it has weak intermolecular forces between the layers so layers easily slide over each other
state 4 properties of graphite
good conductor of electricity and heat
soft
high melting point and boiling point
insoluble
what is one layer of graphite called
graphene
what is a fullerene
molecules of carbon atoms with hollow shapes
what is the name of the fullerene that has 60 carbons
buckminsterfullerene
describe a carbon nanotube
a cylindrical fullerene with a very high length to diameter ratio
what are nanotubes used for
electronics
nanotechnology
materials
what is the law of conservation of mass
no atoms are lost or made during a chemical reaction
the mads of the products is equal to the mass of reactants
what is crude oil
a mixture of very large number of compounds
what is a finite resource
one that will run out
first 4 alkanes
methane
ethane
propane
butane
what is fractional distillation
a process used to separate mixtures of substances with different boiling points
what is combustion
the reaction of fuel with oxygen
when does incomplete combustion occur
when there is not enough oxygen present
what are the 2 types of cracking
catalytic
steam
how do you test for an alkene
react it with bromine water
5 fuels we obtain from crude oil
petrol
diesel
kerosene
heavy fuel oil
liquified petroleum gases
the longer the alkane, the ………. its boiling point
higher
the longer the alkane, the ……….. it is
thicker or viscous
the longer the alkane, the less ……………. it is
flammable
are alkenes saturated or unsaturated
unsaturated
what are the 2 types of chemical bonding
ionic
covalent
metallic
what is the arrangement of ionic bonding
non metal and metal
what is the arrangement of covalent bonding
2 non metals
what is the arrangement of metallic bonding
2 metals
