2(a) group 1

Question 1

what are the group 1 metals known as and why?

Answer 1

alkali metals as they form alkaline solutions when they react with water

Question 2

why do they have similar characteristics and chemical properties?

Answer 2

each have one electrons in their outermost shell

Question 3

what are some of the properties that all group 1 metals share?

Answer 3

• soft metals (easily cut)
• low densities and melting points
• very reactive as only need to lose one electron to become stable

Question 4

equation for G1 metals reaction with water:

Answer 4

2M (s) + H2O (l) –> 2MOH (aq) + H2 (g)
(where M is Li, Na, K, Rb or Cs)

Question 5

how does the reactions with the G1 metals and water change as you go down the table?

Answer 5

the reaction gets more vigorous as you descend the group

Question 6

Lithium reaction with water:

Answer 6

• quite slow
• doesn’t melt
• fizzing can be seen

Question 7

sodium reaction with water:

Answer 7

• Bubbles of gas
• Melts into a shiny ball that dashes around the surface

Question 8

potassium reaction with water:

Answer 8

• Bubbles of gas
• Melts into a shiny ball that dashes around the surface
• Burns with a Lilac-coloured flame

Question 9

what do the alkali metals from from reacting with oxygen?

Answer 9

• metal oxides
• which is why they tarnish when exposed to air

Question 10

equation for the reaction of alkali metals and air:

Answer 10

e.g. lithium + oxygen –> lithium oxide

Question 11

physical trends?

Answer 11

• soft (soft as you go down)
• first 2 are less dense than water
• have relatively low melting points (decrease as move down group)