Question

Calculate the mass of $2.5g$ atom oxygen.

Answer 1

Hint: On the periodic table, oxygen belongs to the chalcogen group. It is an important component in the majority of combustion processes. It is one of the most common elements on the planet's surface.
Formula used:
$Number{\text{ of g atoms = }}\dfrac{{Mass{\text{ of an element}}}}{{atomic{\text{ mass}}}}$

Complete answer:
Number of $g$ atom of oxygen $ = 2.5g$
To find: Mass of oxygen atom
Substituting the values in the above formula,
$Number{\text{ of g atoms = }}\dfrac{{Mass{\text{ of an element}}}}{{atomic{\text{ mass}}}}$
$2.5g = \dfrac{{Mass{\text{ of an element}}}}{{16}}$
Mass of an element $ = 2.5g \times 16$
Mass of an element $ = 40g$
Hence, the mass of oxygen is $40g$.

Additional Information:
Physical properties: In its natural condition, the gas is colorless, odorless, and tasteless. Liquid oxygen has a small paramagnetic property. Except for helium, neon, krypton, and argon, it is reactive and produces oxides with all other elements. In water, it is somewhat soluble. One of the most known allotropes of oxygen is dioxygen. Trioxygen is the most reactive allotrope of oxygen, causing lung tissue damage. This allotrope is known as ozone.
Applications: It's utilized in the production of glass and stone products, as well as in mining. In cases of high pressure, special oxygen chambers are utilized to raise the partial pressure of oxygen surrounding the patient. Melting, refining, and manufacturing steel and other metals are the most common uses of oxygen.

Note:
The sum of the masses of protons, neutrons, and electrons in an atom or group of atoms is called atomic mass. Because electrons have a very low mass compared to protons or neutrons, their mass has no bearing on the calculation.