<h2>Answer:</h2>
a) Group 1
b) Yes, they are very reactive
c) They do not occur freely in nature
e) Soft
f) Francium and Caesium
g) They react explosively to produce hydrogen gas
<h2>Explanation:</h2>
Alkali metals are metals that belongs to Group 1. They are known to be very reactive due to its tendency to donate their lone electron to other element to attain their octet configuration.
Due to their reactive nature, they do not occur freely in nature unless when combined with other elements.
These group1 metals are known to be soft metals due to their low ionization energy. The two most reactive element in the group are Francium and caesium since reactivity of elements increases from top to bottom of the periodic table.
When these metals are exposed to water, they react explosively to produce hydrogen gas.
