Flashcards in GCSE chemistry unit 1 Deck (49)
what is the relative mass of an electron?
1/1840 or negligible
what are the charged of a) protons b) neutrons and c) electrons.
protons +1 or positive
neutrons 0 or neutral
electrons -1 or negative
The relative mass of protons and neutrons are both 1, where are they held?
in the nucleus, the charge here is positive.
electron orbit the _______ in energy levels.
what shell has the highest energy level (out of shell 1, shell 2, shell 3 or shell 4) and how many electrons are on it?
Shell 4 and it holds the maximum of 18 electrons. shells 2 and 3 hold the maximum of 8 electrons and the 1st shell contains 2 electrons.
m- relative atomic mass- number of protons added to number of neutrons.
z- atomic number- this shows the number of protons (the number of electrons is the same.)
X- this is the chemical symbol e.g. C is carbon.
how many Protons neutrons and electrons does sodium have?
protons = 11 because the atomic number is 11
neutrons = 12 because 23 take 11 is 12.
electrons = 11 because the number of protons is always the same on any atom unless its an ion.
what is most of an atom made up of?
what is the charge of any atom?
neutral, there are the same amount of protons and electrons so the charges cancel each other. if any electrons are added or taken away it becomes a charged ion.
an element is made up of all the same type of atom. The periodic table is ordered by atomic mass. what makes atoms different?
the number of subatomic protons in its nucleus.
what is an isotype?
an isotype is an atom with a normal amount of protons and electrons but a changed amount of neutrons. this means the atomic number is still the same but it has a different atomic mass.
the group number is the same number as the number of electrons on the outer shell (vertical columns) what do the periods show?
the number of shells.
what is group 1 on the periodic table.
if a halogen (grp 7) gains an electron during ionic bonding it will have the same atomic structure as a group 8/0 element which can also be called....
what is the middle section of the periodic table called?
which side of the periodic table are metals found on??
the left side- there are lots of them and they take up 3/4 of the space.
what happens as the number of electrons on the outer shell gets closer to 8 or 0?
it becomes more reactive.
metal atoms loose electrons as they do not have many electrons on their out shells. this makes them into positively charged____
non-metal atoms gain the electrons because its easier to fill up their shell rather than get rid of all their electrons.this makes them into negatively charged _____
to work out the charge of an ion: for a metal the charge is the group number, and for a non-metal ___ ______ __ ___ _____ ______ _____ _
Non-metal= group number minus 8
why do oppositely charged ions attract each other?
because of strong electrostatic forces.
when 2 ions of opposite charges bond the charges must balance. for example sodium oxide: Na+ and O2- how many sodium would be needed to cancel out the negative charge from the oxygen?
what is covalent bonding?
when atoms share electrons to get a full outer shell.
what sort of atoms does a covalent bond form between?
when non-metals are bonded in a covalent bond what are they called?
list some properties of gases or liquids bonded by a covalent bond :)
- low melting points (the covalent bond is strong but there are weak intermolecular forces actually holding them together therefore only a low temperature is needed to separate the molecules when they are melted/boiled)
- don't conduct electricity.
when drawing covalent bonds: you use dots for one atom and crosses for the atom, which shell do you draw?
you only have to draw the outer shell.
when drawing a letter diagram for covalent bonding how do you decide how many lines to put in-between the atoms?
the number of lines is the number of electrons shared, this makes the difference between single double and triple covalent bond.
how are metallic bonds formed?
they are formed by the attraction between free electrons and the positive metal ions.
The bond is strong therefore the melting/boiling point is high. what are some other properties of metallic bonds?
they are good conductors of heat and electricity because free electrons can carry a charge or heat energy through the metal. these free electron also make the metal able to slide over each other because of its linear layers. the free electrons keep these layers together when the metal is doing this (ductile and malleable.)