The first model represents the proton and neutron distribution in the nucleus of four helium isotopes. the second image shows the entry for helium in the periodic table. based on the information in the periodic table, which is the most common isotope of helium?

B

Explanation:

Isotopes are elements which have same atomic number but different mass number.

General representation of an element is given as:

where,

Z represents Atomic number

A represents Mass number

X represents the symbol of an element

Thus for helium , which is shown to be

Mass number is defined as the sum of number of protons and neutrons that are present in an atom.

Mass number = Number of protons + Number of neutrons  = 4

Number of neutrons = 4-2 =2

Atomic number is defined as the number of protons or number of electrons that are present in an atom.

Atomic number = Number of electrons = Number of protons  = 2

Thus the representation with 2 protons and 2 neutrons will be the most common isotope of helium.

the supermassive black hole is in the middle of the galaxy.

the answer is c on e2020, bud.