Group 1 Flashcards
(17 cards)
Lithium, sodium and potassium are?
D - alkali metals
When sodium is added to cold water it forms a molten ball which floats on the surface of the water
Explain why this happens
- reaction produces heat (exothermic reaction)
- sodium has a low melting point
- sodium has a lower density than water
Balanced equation for reaction of sodium with water
2Na + 2H2O —> 2NaOH + H2
Electronic configuration of sodium is 2.8.1
Of Potassium it is 2.8.8.1
Explain the similarities and differences in the way sodium and potassium react with cold water by considering their reactions and their electronic configurations.
Similarities:
- both in the same group (group 1)
- react in similar ways
- same number of outer electrons
- both fizz in water and produce hydrogen
- both produce hydroxide/alkaline solution in water
Differences:
- potassium is more reactive
- potassium produces a lilac flame
- potassium’s outer electrons are further away from the nucleus
- potassium has more outer shells so it has more shielding
- potassium outer electron is lost easier than sodium
Give another physical property of lithium sodium and potassium
- soft so easily cut with a knife
Explain in terms of electrons in their atoms why lithium sodium and potassium are in Group 1
(2)
- they all have one outer electrons in the outer shell
A small piece of potassium is added to the water
Describe what you would see in this reaction
- fizzing
- potassium floats
Which one of these is a balanced equation for this reaction
D - 2K + 2H2O —> 2KOH
There is an increase in reactivity of these group 1 metals from lithium to potassium.
Explain this increase in reactivity
- increasing number of shells going down the group
- means increased shielding of outer electron
- less attraction for electron
- easier to lose electrons
Argon is used in filament lamps because it …
D - is inert
Metals are malleable
Explain in terms of their structure why metals are malleable
- atoms arranged in layers and sheets
- easy for the layers to slide over each other
Describe the reactions of lithium sodium and potassium and what would be seen and explain this pattern in reactivity
- you would see fizzing and moving
- floating on the water
- produce hydrogen and a metal hydroxide alkaline solution
- gets smaller
- reactivity increases going down the group so potassium reacts more violently than lithium
- potassium gives a lilac flame and sodium gives a yellow flame
- group 1 react by losing one electron
- electron is more easily lost going down the group
- more electron shells going down the group which increases shielding
- less attraction between nucleus and outer electron going down the group
REACTIVITY INCREASES GOING DOWN THE GROUP BECAUSE THE OUTER ELECTRON IS EASIER TO LOSE BECAUSE OF MORE SHELLS
Which row of the table correctly shows group i and transition metals
B - potassium and caesium, copper and iron
PCCI
Describe the structure of metals in terms of the particles present in their structures
- regular arrangement of positive ions
- surrounded by a sea of delocalised electrons
Explain why metals conduct electricity
- electrons are free to move
- so they carry the charge
Describe what you would see when a small piece of sodium is added to water
- fizzing
- will float and move around
Write the balanced equation for the reaction of sodium with water to form sodium hydroxide and hydrogen
2Na + 2H2O —> 2NaOH + H2
