The table compares some characteristics of two atoms.

Charged Particles

Atom Number of Neutrons Mass Number

X 4 7

Y 5 9

Use the table to determine the number of protons for each atom. Then, choose the statement below that is true about the two atoms.

1. Atoms X and Atom Y are in the same family.

2. Atom X is in a column to the right of Atom Y on the periodic table.

3. Atom X and Atom Y are in the same row on the periodic table.

4. Atoms X and Atom Y are isotopes.

Atom X,

Neutron num = 4, Mass num = 7

Therefore, proton number = Mass num - Neutron num

= 7 - 4

= 3

Atom Y,

Neutron num = 5, Mass num = 9

Therefore, proton number = Mass num - Neutron num

= 9 - 5

= 4

1) False. Atom X belongs to group 3 while atom Y belongs to group 4

2) False. Atom X is in a column on the left of Atom Y

3) True. Atom X and atom Y belong to the same period two on the periodic table

4) Fasle. Atom X and Y are not isotopes because they do not have the same atomic number.

Isotopy is a phenomenon whereby atom of same element have same atomic number but different mass number