Group 2 Flashcards
What do the electron structures end in?
S2
How many valence electrons do they have?
2
What are the reactions?
Lose 2 electrons from the s orbital to from a dispositive (2+) ion
Normally oxidised so therefore they are good reducing agents
What is atomisation energy?
Energy needed to break the bonds holding the atoms together in the metallic lattice
What are 1st and 2nd ionisation energies needed for?
Needed to convert metal atoms into ions with a 2+ charge
Atomic radius down the group…
Increases
Number of electron shells…
Increases so therefore electrons are further from the nucleus
What happens to 1st ionisation energy and why?
Decreases because the atomic radius increases and there are more electron shells, therefore the electrons are further from the nucleus
Melting point down the group…
Decreases
Ionic radius…
Increases
Ions all have a 2+ charge- their is a decreases charge density and weaker attraction between ions and delocalised electrons
What compounds do group 2 form?
Colourless/white compounds
Are group 2 good or bad conductors of electricity?
Goood
High or low melting point?
High
What do group 2 carbonates decompose to form?
An oxide and carbon dioxide
What are the oxidation states of group 2 elements?
0
What are the oxidation states of group 2 compounds?
+2
How does magnesium burn and what does it form?
Burns with a bright white flame to produce magnesium oxide
How do group 2 metals react with HCL?
Form hydrogen gas and a colourless solution
Do group 2 hydroxides become more or less soluble down the group?
More soluble
Do group 2 sulphates become more or less soluble down the group?
Less soluble
What happens to reactivity down the group?
Increases
Do reactions get more or less vigorous down the group?
More
How are hydroxides formed?
By group 2 dissolving in water
How does Mg react with water?
Slowly with cold water
A few bubbles when reacted with steam
Reaction of Ca with water?
Reacts quickly with cold water
Forms bubbles and a cloudy solution
Reaction of Sr with water?
Reacts vigorously with cold water
Forms bubbles of H2
Reaction of Ba with cold water?
Reacts very vigorously with cold water
What is calcium carbonate used for?
In limestone, chalk and marble
Used for road marking, glass and steel manufacture
Also uses as an antacid to treat excess stomach acid
What is magnesium hydroxide used to treat?
Excess stomach acid (antacid tablets)
Why is magnesium hydroxide used in toothpaste?
To neutralise mouth acids- which cause tooth decay
What is titanium used in and why?
Hip replacements as it is strong, resistant to corrosion and low density
Hip replacements as it is similar density to our bones
What are barium compounds used in?
X-rays of the stomach and the digestive system
Barium atoms are heavy and good at absorbing x-rays
