Q43P - Chemistry: Molecular Nature Of Matter And Change

Question

Write the ${}_{\mathbf{Z}}{}^{\mathbf{A}}\mathit{X}$ notation for each atomic depiction

(a)(b) (c)

Step-by-Step Solution

Answer

In an element A represents the mass number and while Z represents atomic number of an element.

$\begin{array}{l}\left(a\right) {}_{18}{}^{38}Ar\\ \left(b\right) {}_{25}{}^{55}Mn\\ \left(c\right) {}_{47}{}^{109}Ag\end{array}$

Step 1 Solution for part (a)

Given, 

Number of protons = 18

Number of electrons = 18 

Number of neutrons = 20

We know, 

Atomic number = number of protons = 18

Atomic mass = number of protons + number of neutrons 

Atomic mass = 18 + 20 = 38

From the above calculation, $\begin{array}{l} {}_{18}{}^{38}Ar\end{array}$

Step 2 Solution for part (b)

Given, 

Number of protons = 25

Number of electrons = 25

Number of neutrons = 30

We know, 

Atomic number = number of protons = 25

Atomic mass = number of protons + number of neutrons 

Atomic mass = 25 + 30 = 55

From the above calculation, $\begin{array}{l}\\ {}_{25}{}^{55}Mn\\ \end{array}$

Step 3 Solution for part (b)

Given,

Number of protons = 47

Number of electrons = 47

Number of neutrons = 62

We know, 

Atomic number = number of protons = 

Atomic mass = number of protons + number of neutrons

Atomic mass = 47 + 62 = 109

From the above calculation, $\begin{array}{l} {}_{47}{}^{109}Ag\end{array}$