Answer : The percent composition of Pb and Sn in atom is, 3.21 % and 96.8 % respectively.
Explanation :
First we have to calculate the number of atoms in 5.5 wt% Pb and 94.5 wt% of Sn.
As, 207.2 g of lead contains
atoms
So, 5.5 g of lead contains
atoms
and,
As, 118.71 g of lead contains
atoms
So, 94.5 g of lead contains
atoms
Now we have to calculate the percent composition of Pb and Sn in atom.


and,


Thus, the percent composition of Pb and Sn in atom is, 3.21 % and 96.8 % respectively.
Answer:
A and B
Explanation:
This is because there was emission of gamma (Y) radiations in both the reactions.
Answer:
H2Br + 2KOH ----- K2Br + 2H2O
Alkali metal - Group 1 metal
Alkaline earth metal - Group 2 metal
Iron triad - metal
Halogens - most are diatomic and are nonmetals - Cl2, Br2, I2
Noble gases - nonmetals and are not reactive due to full valence shell.
Boron group - metalloid
Oxygen group - oxygen molecule - a diatomic molecule composed of oxygen atoms, which are nonmetals.