C4.1.1 Flashcards
What are the Group 1 elements called and why?
They are called the alkali metals because they react with water to form alkaline solutions.
What metal properties do Group 1 elements also have?
They are shiny when freshly cut, good conductors of electricity.
What non-metal properties do the Group 1 elements have?
They are in the solid state at room temperature, but are all soft enough to cut with a knife. Each metal is softer as you go down the group.
What is the trend as you go down the group?
The trends as you go down the group:
- their density increases, though sodium is denser than expected
- their melting point decreases
Why are the Group 1 metals stored in oil?
They react rapidly with oxygen in the air and with water.
What do the metals create when they react with water. For eg, what would happen with sodium?
The alkali metals react with water to produce a metal hydroxide and hydrogen. For example,
2Na(s) + 2H2O(l) —> 2NaOH(aq) + H2(g)
What happens to the reactivity as you go down the group?
The reactivity increases as you go down.
- lithium fizzes steadily and slowly disappears
- sodium melts to form a silvery ball, fizzes vigorously, and quickly disappears
- potassium immediately ignite, burns with a lilac flame, and very quickly disappears
Why does the reactivity go up?
The Group 1 elements all have similar chemical properties because all their atoms have one electron in their outer shell.
- the atomic radius increases, which increases the reactivity
- the attraction between electrons and the nucleus decreases, meaning that there is more shielding
- it is easier to lose an electron from the outer shell as you go down, which is why it becomes more reactive
X —> X+ + e-
