Inorganic Chemistry - Group 1 (Alkali Metals), Lithium, Sodium And Potassium

Question 1

How do the similarities in reactions of these elements with water provide evidence for their recognition as a family of elements?

Answer 1

They have characteristic properties due to the single electron in their outer shell.

All of the metals in group one react vigorously with water to create an alkaline solution and hydrogen.

Question 2

How does lithium react with water?

Answer 2

Fizzes steadily

Question 3

How does sodium react with water?

Answer 3

Melts into a ball then fizzes gently.

Question 4

How does potassium react with water?

Answer 4

Gives off sparks and hydrogen burns with a lilac flame

Question 5

Explain the trend in reactivity in group 1 in terms of electronic configurations

Answer 5

Down the group - easier to lose electrons and form positive metal ions (cations)

It is easier to lose electrons due to the increase in electron shells as you go down the group. This means that there is more electron shielding and so decrease in attraction between the positively charged nucleus and the negatively charged outer shell electrons which can be lost more easily.