Question

an atom x has mass number 31 and electroni configuration 2,8,5 . how many protons and neutrons are present in the atom​

Answer 1

his is the isotope phosphorus-31. It has 15 protons, 15 electrons, and 16 neutrons.

Answer 2

$\overline{\underline{\boxed{\sf GIVEN \darr}}}$

an atom x has mass number 31 and electroni configuration 2,8,5 . how many protons and neutrons are present in the atom

$\overline{\underline{\boxed{\sf SOLUTION \darr}}}$

Mass number of the element X is 31

Electronic Configuration = 2,8,5

So, atomic number = 2 + 8 + 5

Atomic number = 15

We know that Atomic number = No. of protons

Henceforth, number of protons = 15

Now, the formula to get number of neutrons :

• Mass number = No. of Neutrons + No. of protons

Putting the respective values we have

• 31 = No. of Neutrons + 15

• No. of Neutrons = 31 - 15

• No. of Neutrons = 16

$\overline{\underline{\boxed{\sf FINAL\: ANSWERS\darr}}}$

• Number of Protons are 15

• Number of Neutrons are 16