the Periodic table Flashcards
What are group 0 elements known as?
noble gases
noble gases have full outer shells which means ….
they have a very stable electron configuration making them unreactive and do not easily form molecules
boiling points of noble gases increases….
and why
with relative atomic mass (going down the group)
this is because the atoms get larger so the intermolecular forces between forces become stronger = more energy needed to overcome these forces
What are group 1 elements known as?
alkali metals
how many electrons does group 1 have in the outer shell?
1
Group 1 boiling and melting point _______ as you go down the group
decreases
Why does Group 1 become more reactive as you go down the group?
because the outer electron gets further away from the influence of the nucleus, so it can be lost more easily
Why are alkali metals stored under oil?
because they react vigourously with oxygen and water, inclucding moisture in the air
alkali metal + water =
metal hydroxide + hydrogen gas
Group 1 metals have _________ density
low
which group 1 metals float because they are less dense than water?
sodium, lithium and potassium
metal hyrdoxide dissolved in water =
alkaline solution
alkali metals + non-metals =
ionic compounds
What are group 7 (which are non-metals) known as?
halogens
why do group 7 elements have similar reactions
because they all have 7 electrons in their outer shell
reactivity in group 7 elements ________ as you go down the group
decreases
why does reactivity in group 7 elements decrease as you go down the group
because the outer shell gets further away from the nucleus, so it is less easy to gain an electron
The further down Group 7 the element is ________ its relative molecular mass, melting point and boiling point
the higher
Halogens + metals =
ionic salts
what happens when halogens and metals react?
a halide ion with a negative charge (-1) is formed
what happens when alkali metals react with non-metals?
ions
a metal ion with a positive charge (+1) is formed
A more reactive halogen will __________ a less reactive halogen from an _____________ of its salt
displace
aqueous solution
where are transtion metals?
in the centre of the periodic table, between groups 2 and 3
what are the features of transition metals?
- form coloured compounds
- they have ions with different charges
what are the properties of transition metals?
good conductors of heat and electricity can be easily bent or hammered into shape dense strong shiny
what can transition metals be used for?
catalysts to speed up chemical reactions
how did Newlands arrange the elements in the periodic table?
in order of atomic weight
Why was ordering elements in order of atomic weight a bad thing?
because some of the elements were in the wrong place
what did medeleev realised and what did he do
that some elements had yet to be discovered and left gaps to allow for their discovery
used the periodic table to predict the existence and properties of new elements
he also reordered some elements
How did Mendeleev reorder the elements?
each element was placed in a group with elements that had similar properties
what did scientists realise when subatomic particles were later discovered
that Mendeleev had organised the elemnts in order of increasing atomic number
transition metals are ______ reactive than alkali metals
less
