Question

An atom has a mass number 209 and atomic number is 82, the number of neutrons
present in it is
a 147
b 209
c 82
d 127​

Answer 1

Answer:

d 127

Explanation:

there are 82 protons and electrons in the following atom because number of electrons/protons is equal to the atomic number. Mass of an atom is due to protons and neutrons so mass of following atom is equal to

mass no. = neutrons+protons

209=neutrons+82

neutrons=209-82

neutrons=127