alkali metals

Question 1

what are the 4 physical properties of alkali metals

Answer 1

soft
has a low melting and boiling point
density increases down the group
melting and boiling points decrease down the group

Question 2

what are the 3 chemical properties of alkali metals

Answer 2

valence electron
highly reactive 
reactivity increases down the group
alkali metal + water -> water + hydrogen
soluble in water!!

Question 3

why does the reactivity of alkali metals change?

Answer 3

reactivity increases down the group as the valence electron is further from the nucleus, which increases the ease of losing electrons

Question 4

list down the alkali metal + h2o reactions

Answer 4

lithium + h2o -> lithium hydroxide + hydrogen, metal floats on water
sodium + h2o -> sodium hydroxide + hydrogen, metal darts around, yellow flame
potassium + h2o -> potassium hydroxide + hydrogen, metal darts around, lilac flame