Question

How do you find the protons, neutrons, and electrons for a bromine (1-) anion with a mass number of 80?

Answer 1

Hint: In an element in periodic table the number of electrons is nothing but the atomic number of the particular element. If we know the number of electrons we can find the element easily by using a periodic table.

Complete answer:
- In the question it is given that to find the number of protons, neutrons and electrons for an anion.
- By seeing the given anion we can easily see that bromine accepts one electron and becomes a bromide anion.
- We know the atomic number of bromine.
- The atomic number of bromine is 35, which means the bromine element contains 35 electrons and 35 protons.
- But in the question it is given that to find the number of protons and electrons for bromide anion.
- Bromide anion means bromine accepts one electron so the number electrons in bromide anion will be 36.
 - We know that the sum of the number of protons and number of neutrons will be the mass number of the element.
Number of protons + number of neutrons = mass of the element
- The mass number of bromine is 80.
- Number of protons in bromine are 35.
- Therefore the number of neutrons = 80 - 35 = 45.
- So, the number of protons, electrons and neutrons present in bromide anion is 35, 36 and 45 respectively.

Note:
By knowing the mass number and number of protons of an element we can easily calculate the number of neutrons present in a particular molecule. The mass number of an element will be higher than the number of protons and number of neutrons present in the element.