Anwser keyClick on Alkali Metals (left bar) and answer the following questions. a. What is the group number? . Are these metals reactive? b. Do these metals occur freely in nature? c. How many electrons are in their outer shell? d. What are the three characteristics of ALL metals? . e. Are these metals soft or hard? f. Name the two most reactive elements in this group? And g. What happens when they are exposed to water? . wab quest answer key

Explanation:

Alkali metals are the metals which belong to group 1 of the periodic table. As these elements have one valence electron so they are highly reactive in nature.

Some characteristics of metals are as follows.

When these metals react with water then it leads to the formation of metal hydrides.

For example,

Thus, we can conclude the following for alkali metals:

a. What is the group number? - Group 1.

Are these metals reactive? - Yes

b. Do these metals occur freely in nature? - No

c. How many electrons are in their outer shell? - 1 valence electron

d. What are the three characteristics of ALL metals?

e. Are these metals soft or hard? - Both

f. Name the two most reactive elements in this group? - Lithium And  Sodium

g. What happens when they are exposed to water? - They form hydrides.

considering the question as per the attachment

here we can see that the radon nuclide has 222 as the atomic mass number and 86 as the atomic number.

when it undergoes nuclear fission it gives polonium which has atomic mass number as 218 and atomic number will be 84 along with a helium nucleus which has 4 atomic mass number and 2 as its atomic number.

222 = 218 + 4 (atomic mass number)

86 = ? + 2; therefore ? = 86-2 = 84.

the atomic mass number of polonium will be 84.