Answer:
Alkali metals are any of the elements found in Group IA of the periodic table (the first column). Alkali metals are very reactive chemical species that readily lose their one valence electron to form ionic compounds with nonmetals. All elements in the alkali metal group occur in nature.
Explanation:
The first one is Earthquake, second one is nuclear fission, and the last one idk
Total→$120×80=$9600__suppose all 80 is girls
extra→$9600-$9210=$390
difference→$120-$105=$15
opposite→$390÷$15=26boys
girls→80-26=54
