According to the image, identify the number of neutrons in the most common isotope of aluminum.
a) 13
b) 14
c) 26
d) 27

The number of neutron in the Aluminium Isotope is :

B. 14

Explanation:

Isotopes : These are the atoms which have same atomic number but have different mass number.

This image shows the average atomic mass of Al element because it is in decimals.

Atomic mass = 26.98154

(Note : mass number of single isotope can never be in decimals)

It is the average of mass of different isotopes of Al

Major Isotopes of are :

mass of Al given in image(26.98) is nearly equal to mass of 2nd isotope(27)

mass of

Now calculate the neutron in

Number of neutron = mass number - atomic number

                                = 27 - 13

Number of neutron = 14

(Atomic mass is same as mass number)

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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