One outer electron. More reactive down the group.
Lithium, sodium and potassium are Group 1 metals. They are soft, have relatively low melting points for metals and are shiny when freshly cut. Their surfaces quickly tarnish in air.
Each atom has 1 outer electron. In reactions, it is lost to form a +1 ion (a positively charged particle). Hydrogen is not an alkali metal.
These metals react with water to form a metal hydroxide and hydrogen gas. The hydroxide makes the solution alkaline.
Observations from teacher demonstrations; these reactions are not a home activity.
With oxygen, these metals form oxides; freshly cut surfaces tarnish. With chlorine, they form white solid metal chlorides.
Lithium burns crimson-red, sodium yellow-orange and potassium lilac in these burning reactions. All three react vigorously with chlorine.
Down Group 1, atoms have more shells. The outer electron is further from the nucleus and more shielded by inner electrons. It is attracted less strongly and lost more easily.
So potassium is more reactive than sodium, and sodium is more reactive than lithium.
One outer electron; water makes hydroxide + hydrogen; reactivity increases down the group.
Look closely. Use the clues.
Use the pictures and patterns.
One point for each answer you get right first time.
No timer. Take your time and use a clue whenever you need one.