Chapter 3.3, Problem 3RQ

Interpretation Introduction

Interpretation: The given table needs to be completed.

Symbol	Number of Protons	Number of neutrons	Number of electrons
$\text{F}$
	$28$	$31$
		$20$	$19$

Concept Introduction:

The number of protons in an atom is called the atomic number. The addition of the number of protons and neutrons, is equal to the mass number. When the numbers of neutrons are different the mass number of elements is changes but atomic number remains unchanged that consider as an isotope of the element.

Answer to Problem 3RQ

The complete table is

Symbol	Number of Protons	Number of neutrons	Number of electrons
$\text{F}$	$9$	$10$	$9$
$\text{N}\text{i}$	$28$	$31$	$28$
$\text{K}$	$19$	$20$	$19$

Explanation of Solution

Calculation for symbol, $\text{F}$

The number of protons is equal to the atomic number of the element. The given symbol is of Fluorine. According to the periodic table, atomic number of Fluorine (F) is $9$ . So, the number of protons in Fluorine: $9$

It is known that the number of electrons is equal to the number of protons.So, the number of Electrons in Fluorine: $9$

So, the atomic number in fluorine = $9$ and average mass number in fluorine = $\text{19}$

Number of neutrons in $\text{F}$ :

Put the given values in the formula, The mass number= number of protons + number of neutrons.

  $\text{19 = 9 + N}$

  $\text{N = 10}$

Calculation for symbol, number of protons $\left(28\right)$ and Number of neutrons $\left(31\right)$

The number of protons is equal to the atomic number of the element and the number of electrons is equal to the number of protons. In the table, number of protons are given $28$. So, the number of electrons: $28$ . It is also given that the number of neutrons $31$ .

According to the periodic table, Nickel’s atomic number is $28$ and also, number of neutrons are $31$ . Symbol of Nickel is Ni.

Calculation for symbol, number of neutrons $\left(20\right)$ and Number of electrons $\left(19\right)$

The number of protons is equal to the atomic number of the element and the number of electrons is equal to the number of protons. In the table, number of electrons are given $19$. So, the number of electrons: $19$ .

According to the periodic table, Potassium’satomic number is $19$ and also, number of neutrons are $20$ . Symbol of Potassium is K.

So, the complete table is

Symbol	Number of Protons	Number of neutrons	Number of electrons
$\text{F}$	$9$	$10$	$9$
$\text{N}\text{i}$	$28$	$31$	$28$
$\text{K}$	$19$	$20$	$19$

Conclusion

The protons are the equal to number of electrons and the numbers of protons explains the atomic number of the element.