Question

the mass of single atom of an element X is 2.65×10^23 g. what is its gram atomic mass? what could this element be?

Answer 1

The atomic mass of an element is numerically equal to the mass of 1 mole of its atoms.

1 mole of atoms = 6.022 × 1023 atoms

Now, 1 atom of element X has mass = 2.65 × 10-23g

So 6.022 × 1023 atoms of element X have mass = 2.65 × 10-23×6.022 × 1023

                                                                       = 15.96 = 16g

                                       

Atomic mass of the element X is 16u.

Oxygen is the element with atomic mass 16 and having  symbol O.

Answer 2

The atomic mass of an element is numerically equal to the mass of 1 mole of its atoms.

1 mole of atoms = 6.022 × 1023 atoms

Now, 1 atom of element X has mass = 2.65 × 10-23g

So 6.022 × 1023 atoms of element X have mass = 2.65 × 10-23×6.022 × 1023

                                                                       = 15.96 = 16g

                                       

Atomic mass of the element X is 16u.

Oxygen is the element with atomic mass 16 and having  symbol O.