Question

The difference between ions and atoms in of -

• A. relative size
• B. configuration
• C. presence of charge
• D. mass of nucleus

Answer 1

Answer: (A), (B), (C)

presence of charge

• Atom is the smallest unit of matter. It is indivisible and consists of protons, electrons, and neutrons.
• Atoms, where the electrons and protons are not equal, are called ions. Ions are charged particles. They can be either positively charged ions (cations) or negatively charged ions (anions).

Explanation of correct option:

(A) Relative Size

• The size of a cation (positively charged ions) is always smaller than the parent atom.
• The size of an anion (negatively charged ions) is always larger than the parent atom.
• Hence the size of atom may be less or more according to the above two conditions given.

(B) configuration

• The electronic configuration of atoms and ions is different because the number of electrons in both is different.
• In the case of cation, the number of electrons is lesser than the parent atom.
• In the case of an anion, the number of electrons are more than the parent atom.
• Hence from the above data we may conclude that the electronic configuration for an ion can be less or more than the atom , depending on the condition whether it is anion or cation , but the configuration of atom remains same at all conditions , because it has no charge.

(C) presence of charge

• Atoms are electrically neutral i.e net charge on the atom is zero. The number of protons and electrons are equal in atoms.
• The cations are positively charged i.e. they acquire a positive charge by losing electrons. The number of electrons is less than the number of protons.
• The anions are negatively charged i.e. they acquire a negative charge by the gain of electrons. The number of electrons is more than the number of protons.
• Hence we may conclude that atoms are not electrically charged , whereas ions are charged.

Explanation of incorrect option:

(D) mass of nucleus

• The mass of the nucleus is equal in atoms and ions because the number of protons and the number of neutrons are equal in atoms and ions.
• Mass of nucleus = Mass of protons + mass of neutrons

Conclusion: Hence, option(A), (B), and (C) is correct.