Question

A nitrogen atom has 7 protons, and the most common isotope of nitrogen has 7 neutrons. A radioactive isotope of nitrogen has 8 neutrons. Write the atomic number and mass number of this radioactive nitrogen as a chemical symbol with a subscript and superscript.

Short answer

The chemical symbol for radioactive nitrogen is ¹⁵₇N, which also represents its atomic number and mass number. The mass number is represented in superscript, while the atomic number is written in subscript.

Step-by-step solution

Definition of atomic number and mass number

Each atom's atomic number is the number of protons in its nucleus. The mass number of an element is the sum of its protons and neutrons.

The study of the properties of a given element requires the use of atomic and mass numbers. They are used to describe the pattern of electron organisation, which is useful in the investigation of chemical interactions.

Calculation of mass number of a nitrogen atom 

Nitrogen has seven protons and seven neutrons. A radioactive isotope of N, on the other hand, has eight neutrons.

Because the mass number is equal to the sum of protons and neutrons, the mass number of a radioactive isotope can be computed using the formula:

$\text{Mass} \text{number}=\text{Number of protons}+\text{Number of neutrons}$

It is given that

Number of protons = Atomic Number = 7;

Number of neutrons in radioactive nitrogen = 8.

Now, substitute the values into the formula.

$$\begin{gathered} \text{Mass} \text{number} \text{=} \text{7} \text{+} \text{8} \\ =15 \end{gathered}$$

Thus, the mass number of radioactive nitrogen is 15.

Chemical symbol of radioactive nitrogen 

The chemical symbol of an element is the initial letter of the element with atomic mass written above the symbol as superscript and atomic number below the symbol as a subscript.

Thus, the chemical symbol of nitrogen is¹⁵₇N.