Question

Some elements have different atomic number and same mass number (give reason)

Answer 1

hey!!

here is your answer....

=> so basically, according to my knowledge, These types of elements are known as Isotopes. These elements have the same number of protons and electrones. But have different number of neutrond. So, their mass differs.

Mass of an element = Atomic number + neutrons.

Atomic number ( number of electrons)

this is same in both the elements, but neutrons is different , so mass is also different.

example is Carbon 12 and Carbon 14

Atomic number of carbon atom is 6, both are carbons, so the protons and electrons are same in both the elements, but the number of neutrons differs,

neutrons in carbon 12 are, 6 and number of neutrons in carbon 14 are 8.

(carbon 12) and (carbon 14) are known as the Isotopes of carbon. The numbers 12 and 14 are the atomic masses of the respective Isotopes.

mass of carbon 12 is 12 amu

mass of carbon 14 is 14.

let's take carbon 12, electrons are 6 and neutrons are 6...

6 + 6= 12.

for carbon 14,

electrons are 6

neutrons are 8

6+8 = 14 amu.

hope you understand!
hope it helps !

Answer 2

The full chemical symbol for an element shows its mass number at the top, and itsatomic number at the bottom. This symbol tells you that the chlorine atom has 17 protons. It will also have 17 electrons, because the number of protons and electrons in an atom is the same.