Show that atomic nuclei of different elements have different sizes.

Assertion : ""_(14)Si^(30),""_(15)P^(31) and ""_(16)S^(32) are a group of isotones. Reason : Isotones are atoms of different elements having different mass numbers and atomic numbers but same number of neutrons in their nuclei.

Atoms of different elements have the same mass .

Consider the following stetements in reference to the structure of atom 1. Isopes are the atoms of the same element having same atomic number but different mass - numbers . 2. Isobars are the atoms of different elements having different atomic number of different atomic number but same mass - number . Which of above statement is/are correct ?

Look at the two atomic models. Do the two atoms represent different elements or different isotopes? Explain.

The atoms of different elements having same mass number but different atomic number are known as isobars. The sum of protons and neutrons, in the isobars is always different.

Assertion (A) : The isotopes are the atoms of the same element with different atomic masses. They require different positions in the periodic table. Reason (R) : Variable number of neutrons in the nuclei of the atoms of same elements leads to the different atomic masses.