How many protons (p)and neutrons (n)are in an atom of Sr?
A)38 p,52 n
B)38 p,90 n
C)52 p,38 n
D)90 p,38 n

Question

How many protons (p)and neutrons (n)are in an atom of  Sr?
A)38 p,52 n 
B)38 p,90 n 
C)52 p,38 n 
D)90 p,38 n

Quizplus · Accepted Answer

The atomic number of Strontium (Sr) is 38, which means it has 38 protons. The number after the element symbol (5343) is the mass number, which is equal to the sum of protons and neutrons.

So, 
mass number = number of protons + number of neutrons 
5343 = 38 + number of neutrons 
number of neutrons = 5343 - 38 = 5305

Therefore, the atom of 11ea7a5e_3e2e_a457_89bd_f75721d58a67_TB5343_11 Sr has 38 protons and 5305 - 38 = 5267 neutrons. 
Rounded to the nearest whole number, the answer is 38 p, 52 n.

How Many Protons (P)and Neutrons (N)are in an Atom of