Question

arrange the species of each group in increasing size: a)o,o^-,o^2-
b)al^3+,mg^2+
c)N,O,P,as
d)al^3+,mg^2+,Na^+​

Answer 1

Answer:

a)O<$O^-$<$O^2^-$

b)$Mg^2^+$>$Al^3^+$

c)As>P>N>O

d)$Al^3^+<Mg^2^+<Na^+$

Explanation:

a)Size of anion is greater than parent atom because they have more electrons and the number of protons is the same. Thus the force of nuclear pull is decreased due to the increase in the number of electrons and they move far away thus increasing the size of the atom.

b)This is because both have different number of protons but the same number of electrons and as we know greater is the number of protons, greater is the nuclear pull, the size of $Al^3^+$ is less than that of $Mg^2^+$.

c)This is because size increases on going down the periodic table and decreases on going across a period.

d)This is because all of them have different number of protons but the same number of electrons and as we know greater is the number of protons, greater is the nuclear pull, the size of $Al^3^+$ is less than that of $Mg^2^+$ whose size in turn is less than that of $Na^+$.