group 1 - the alkali metals

Question 1

what are the properties pf the alkali metals?

Answer 1

• they are very reactive

- all react vigorously with water

Question 2

what happens when they react with water

Answer 2

• react vigorously and produce fizzing

- produce a metal hydroxide solution

Question 3

what happens when they react with oxygen?

Answer 3

• form metal oxides

- form different types of oxides depending on the metal

Question 4

what happens as you go further down the group and why?

Answer 4

• they become more reactive down the group (as atomic number increases)
• the atoms lose the electrons more easily because there is only one to lose, and because the outer shell is furthest from the nucleus so there is a weak attraction between the electrons and the nucleus

Question 5

what ion do they form?

Answer 5

1+

Question 6

physical properties

Answer 6

• are soft
• low melting points
• low densities (sodium, lithium, potassium can float on water)
• melting point decreases as you go down

Question 7

chemical properties

Answer 7

w/ water:

• produce metal hydroxide + hydrogen
  e. g : sodium + water —> sodium hydrogen. 2Na (s) + 2H2O (l)—>2NaOH (aq) + H2 (g)

Question 8

what happens with very reactive metals (e.g potassium) :

Answer 8

energy of reaction causes hydrogen to burn as reaction takes place

Question 9

chemical equation of reaction of alkali metal with water

Answer 9

2Na(s) + 2H20(l) —> 2NaOH(aq) + H2

Question 10

what does lithium do when it reacts with water

Answer 10

moves around the surface, fizzes

Question 11

What does sodium do when it reacts with water

Answer 11

it moves on the surface and melts

Question 12

what does the potassium do it reacts with water

Answer 12

floats on surface, hydrogen gas ignites and burns