group 1- the alkali metals

Question 1

how many electrons do group 1 have in their outer energy level/ shell?

Answer 1

1 electron

Question 2

describe the reactivity series of group 1 alkali metals when reacting with oxygen

Answer 2

all group 1 metals react rapidly with oxygen

they get more reactive as we move down group 1

Question 3

how is lithium reacted with oxygen?

at the end of the reaction, what type of ions are gained?

Answer 3

2 lithium atoms are required for 1 oxygen atom
this is so that energy levels of all elements are full

the 2 lithium atoms have lost 1 electron each, this forms a positive ion on each lithium atom (+1)(+1)
and the oxygen atom has gained 2 electrons making it a negative ion of 2-
2- is written outside the bracket of the structure on the top right hand corner

Question 4

what is the equation for the reaction of lithium and oxygen?

Answer 4

4Li + O2 -> 2Li2O
produces lithium oxide

2 lithium atoms for every oxygen atom
oxygen atoms are diatomic
Li + O2 -> Li2O
to balance :
4Li + O2 -> 2Li20

Question 5

how do group 1 metals react with group 7 metals?

Answer 5

very rapidly

metal atom loses electrons becomes positive ion
(non-metal atom gains electrons and becomes negative ion)

Question 6

give the equation for lithium and chlorine then balance the equation.

Answer 6

Li + Cl2 -> LiCl

2Li+ Cl2 ->2LiCl

Question 7

how do group 1 metals react with water?

Answer 7

very rapid fizzing

gas is produced

Question 8

what is lithium hydroxide an example of ?

Answer 8

alkali

Question 9

what is the symbol equation for

lithium + water->lithium hydroxide + hydrogen

Answer 9

2Li + 2H20 -> 2LiOH + H2

Question 10

why do elements in group 1 get more reactive as we move down?

Answer 10

moving down the group, the outer electron is less attracted to the nucleus therefore easier to lose
this is because of :
-the great distance between the positive nucleus and the negative outer electron
-the outer electron is shielded from the nucleus by the internal energy levels

Question 11

which loses its outer electron easiest in order

Answer 11

lithium loses outer electron easy
Sodium loses outer electron easier than lithium
potassium loses its outer electron even easier than sodium

Question 12

moving down the group, why is the outer electron is less attracted to the nucleus therefore easier to lose?

Answer 12

this is because of :

• the great distance between the positive nucleus and the negative outer electron
• the outer electron is shielded from the nucleus by the internal energy levels

Question 13

properties of alkali metals (group 1)

Answer 13

• Soft metals that can be cut with a knife
• Relatively low melting points
• Low density(Li, Na & K are less dense than water).
• React very rapidly

Question 14

all group one metals form what after a chemical reaction has taken place?

Answer 14

forms +1 ion (e.g Na+)