Chapters 4, 11 and 12-The Periodic Table, Alkali Metals and Halogens Flashcards
In what order is the periodic table arranged?
In order of atomic number
Where are metals located in the Periodic Table?
On the left-hand-side
Where are non-metals located in the Periodic Table?
On the right-hand-side
Where does the stepped line which separates the metals and non-metals start?
It starts below boron.
Do metals conduct electricity?
Yes, they are good conductors of electricity.
Do non-metals conduct electricity?
No, they are poor conductors of electricity (except graphite and silicon).
Do metals form acidic or basic oxides?
They form basic oxides (if they are soluble in water, they dissolve to form solutions with a pH greater than 7).
Do non-metals form acidic or basic oxides?
They form acidic oxides (if they are soluble in water, they dissolve to form solutions with a pH less than 7).
Do metals react with acids or bases to form salts?
They react with acids to form salts.
Do non-metals react with acids or bases to form salts?
They react with bases to form salts.
What does the group number tell us?
The number of electrons in the outer shell
What does the period number tell us?
The number of shells occupied
Why do elements in the same group have similar chemical properties?
They have the same number of electrons in their outer shell; the chemical properties depend on the number of electrons in the outer shell.
What are the elements in group 0 called?
Noble gases
How many electrons do the noble gases have in their outer shell?
They have 8 electrons in their outer shell (apart from helium, which has 2).
Why are the noble gases unreactive?
They do not need to lose, gain or share electrons in a chemical reaction to become stable (and their outer shell is full).
What are the elements in group 1 called?
The alkali metals
Do the alkali metals have low or high melting and boiling points and do they increase or decrease down the group?
They have very low melting and boiling points for metals and they decrease down the group.
Do the alkali metals have low or high densities and do they increase or decrease down the group?
They have low densities which increase down the group, but not regularly. Lithium, sodium and potassium are all less dense than water and so float on it.
Are the alkali metals hard or soft and do they become harder or softer down the group?
They are very soft and can be easily cut with a knife, becoming softer as you go down the group.
Are the alkali metals shiny?
They are shiny and silver when freshly cut but tarnish very quickly on exposure to air.
Why are lithium, sodium and potassium stored under oil?
To stop them reacting with oxygen or water vapour in the air.
Why mustn’t you touch any of the alkali metals with your bare hands?
There could be enough sweat on your skin to give a reaction, producing lots of heat and a very corrosive metal hydroxide.
Give four general observations when an alkali metal reacts with water.
It moves around on the surface of the water (hydrogen not given off symmetrically around the metal).
It fizzes/effervesces(hydrogen gas produced).
It floats.
It gets smaller and eventually disappears.
What is a safety point to be noted for when alkali metals react with water?
Use a safety screen as hydrogen gas is explosive.
What do alkali metals form when they react with water?
They all react with water to form a solution of metal hydroxide and hydrogen gas.
How do alkali metals react with air?
They tarnish when exposed to air as they react with oxygen in the air to form an oxide.
Out of lithium, sodium and potassium, which tarnishes the fastest and which tarnishes the slowest?
Potassium tarnishes the fastest and lithium tarnishes the slowest.
What coloured flames do lithium, sodium and potassium burn with?
Lithium burns with a red flame to form lithium oxide, sodium burns with a yellow/orange flame to form sodium oxide and potassium burns with a lilac flame to form potassium oxide.
What does the metal hydroxide dissolve in water to produce?
An alkaline solution which turns Universal Indicator (UI) purple.
Does reactivity increase or decrease down group 1?
It increases; the reactions get faster and more vigorous down the group.
Why does reactivity increase down group 1?
The number of shells increases down the group so the outer electron is further away from the positive nucleus and so is less strongly attracted to it; it is easier to be lost which makes the atom more reactive.
Predict some properties of francium.
It is very soft.
It has a lower melting and boiling point than Caesium; it will be around room temperature.
It is more dense than Caesium.
It reacts explosively with water to produce francium hydroxide and hydrogen.
What colour is chlorine and what is its state at room temperature?
Chlorine is a green gas at room temperature.
What colour is bromine and what is its state at room temperature?
Bromine is a red-brown liquid at room temperature but forms an orange vapour (low boiling point).
What colour is iodine and what is its state at room temperature?
Iodine is a dark grey solid at room temperature but forms a purple vapour (sublimes).
Predict the colour of fluorine and its state at room temperature.
Fluorine is a yellow gas at room temperature.
Predict the colour of astatine and its state at room temperature.
Astatine is a black solid at room temperature.
What are the elements in group 7 called?
The halogens
Does reactivity increase or decrease down the group?
Reactivity decreases down group 7 e.g. bromine is less reactive than chlorine.
Why does reactivity decrease down group 7?
The number of shells increases down the group, so the electron being gained is further away from the positive nucleus and so is less strongly attracted to it; it is harder to gain an electron which makes the atom less reactive.
What happens in a displacement reaction?
A more reactive halogen displaces a less reactive halogen from a solution of one of its salts.
What coloured solution is seen if bromine is formed in a displacement reaction?
The solution becomes orange as bromine is formed.
What coloured solution is seen if iodine is formed in a displacement reaction?
The solution becomes brown (orange if very dilute) as iodine is formed.
What is a safety point to be noted when handling halogens?
The halogens have extremely poisonous vapours and so have to be handled in a fume cupboard/fumehood.
In a displacement reaction between chlorine and potassium bromide, what has been reduced and what has been oxidised?
In this reaction, the chlorine has been reduced as it gains electrons and the bromide ions have been oxidised as they have lost electrons. The chlorine is the oxidising agent.
