<u>Answer:</u> The correct answer is Option 4.
<u>Explanation:</u>
There are three sub-atomic particles present in an atom. They are: electrons, protons and neutrons.
Protons constitute in each and every atom.
The charge on proton is of equal magnitude as that of electron but having opposite sign. Proton carry a positive charge and electron carry a negative charge.
Protons and neutrons, both determine the mass of an atom.
Mass of 1 proton = 1.007276 u
Mass of 1 neutron = 1.008664 u
Mass of 1 electron = 0.00054858 u
Mass of proton is almost same as that of neutron but is more than the mass of electron.
Hence, the correct answer is Option 4.
All nickel atoms would have the same number of protons or atomic number.
D milk turning sour
the other options are physical changes