Combined Higher Flashcards
How is the modern periodic table ordered?
by atomic number
How were the early lists of elements ordered?
by atomic mass
Why did Mendeleev swap the order of some elements?
To group them by their chemical properties
Why do elements in a group have similar chemical properties?
They have the same number of electrons in their outer shell
Where are the metals and non-metals located in the periodic table?
Metals - left
Non-metals - Right
What name is given to the group 1 elements?
Alkali metals
Why are the alkali metals named this?
Because they produce a metal hydroxide (an alkali) when they react with water
Why does the reactivity of the alkali metals increase down the group
They get larger as you go down
So the outermost electrons are further away from the nucleus,
meaning there is a weaker electrostatic force of attraction,
and more shielding from the extra electron shells
and therefore it is EASIER TO LOSE an electron.
Why does the reactivity of the halogens decrease down the group?
They get larger as you go down
So the outermost electrons are further away from the nucleus,
meaning there is a weaker electrostatic force of attraction,
and more shielding from the extra electron shells
and therefore it is HARDER TO GAIN an electron.
What is the name given to group 7 non-metals?
Halogens
How does the melting point for the halogens change as you go down group 7?
Melting point increases - weak intermolecular forces get stronger
What is a displacement reaction?
When a more reactive element displaces a less reactive element from its compound.
Why are the noble gases inert?
Because they have a full outer shell
Why did mendeleev leave gaps in his periodic table?
To leave room for elements not yet discovered
Give the general equations for the reactions of alkali metals with oxygen, chlorine and water
Metal + Oxygen = Metal oxide
Metal + Chlorine = metal chloride
Metal + water = metal hydroxide + Hydrogen
