Chapter 4.3, Problem 17PP

Interpretation Introduction

Interpretation:

Name, number of protons, neutrons and electrons in an atom that has a mass number of 55 and number of neutrons is the sum of its atomic number and 5 are to be determined.

Concept introduction:

Proton is a subatomic particle that carries a positive charge. An electron is a subatomic particle that carries a negative charge. Neutron is a subatomic particle with no charge. Mass number is considered as the sum of the atomic number and neutrons in the nucleus.

Answer to Problem 17PP

There are 25 protons, 25 electrons and 30 neutrons and the element is Manganese.

Explanation of Solution

$\text{Atomic number}\text{(Z)=}{\text{Number of electrons (N}}_{\text{e}}\text{)= Number of protons}{\text{(N}}_{\text{p}}\text{) }$

$Massnumber={\text{Number of neutrons (N}}_{\text{n}}\text{)+ Number of protons}{\text{(N}}_{\text{p}}\text{) }$

Now, it is given that:

${\text{Number of neutrons (N}}_{\text{n}}\text{)+ Number of protons}{\text{(N}}_{\text{p}}\text{)=55}$

And ${\text{Number of neutrons (N}}_{\text{n}}\text{)= Number of electrons}{\text{(N}}_{\text{6}}\text{)+5}$

Therefore, ${\text{Number of neutrons (N}}_{\text{n}}\text{)=30}$

$\text{Number of electrons}{\text{(N}}_{\text{e}}\text{)=25}$

And $\text{Number of protons}{\text{(N}}_{\text{p}}\text{)=Number of electrons}{\text{(N}}_{\text{e}}\text{)=25}$

Now, in the modern periodic number the element with atomic number 25 is Manganese.

Conclusion

The element is Manganese, and has 25 protons, 25 electrons and 30 neutrons.