High School

Determine o número de prótons, nêutrons e elétrons representados por [tex]${}^{136}B^{2+}$[/tex]. As opções são:

A. 56, 82 e 56

B. 56, 82 e 54

C. 56, 82 e 58

D. 82, 138 e 56

E. 82, 194 e 56

Answer :

Sure, let's break it down step-by-step to find the correct answer for the number of protons, neutrons, and electrons in [tex]\(^{136} \text{Ba}^{2+}\)[/tex]:

1. Identify the element:
- The notation [tex]\(^{136} \text{Ba}^{2+}\)[/tex] tells us that the element is Barium (Ba).
- The atomic number (Z) for Barium (Ba) is 56. This means a neutral Barium atom has 56 protons.

2. Determine the number of neutrons:
- The mass number (A) is given as 136.
- The number of neutrons is found by subtracting the atomic number from the mass number.
[tex]\[
\text{Number of neutrons} = A - Z = 136 - 56 = 80
\][/tex]

3. Determine the number of electrons:
- The notation [tex]\(Ba^{2+}\)[/tex] indicates that the Barium atom has lost 2 electrons.
- A neutral Barium atom would have the same number of electrons as protons, which is 56.
- Since it has lost 2 electrons:
[tex]\[
\text{Number of electrons} = 56 - 2 = 54
\][/tex]

So, the number of protons, neutrons, and electrons in [tex]\(^{136} \text{Ba}^{2+}\)[/tex] is:
[tex]\[
\text{Protons} = 56, \quad \text{Neutrons} = 80, \quad \text{Electrons} = 54
\][/tex]

Based on our step-by-step calculation, the correct answer is:

b) 56, 80, and 54