Question

The wrong statement among the following is:
A. nitrogen atom, nitride ion have same atomic number
B. aluminium atom and its ion have same mass number
C. iron atom, ferrous ion have same electronic configuration
D. Effective nuclear charge is the same in both chlorine atom, chloride ions.

Answer 1

Hint: Atoms are the smallest particles of matter. They make up everything around us. Elements are only one type of atom. It has protons, electrons and neutrons. The number of protons is equal to the number of electrons. The number of protons helps to identify the atom equal to the atomic number of the atom.

Complete step by step solution:
Protons are the positively charged particles. Neutrons are the neutral particles. It has no electric charge. It is found inside the nucleus. While electrons are the negatively charged particles found outside the nucleus of an atom, in the electron levels. Each orbit or level can hold a maximum of electrons. Electrons are involved in the formation of chemical bonds.
Now we have to find the wrong statement from the given options. So let’s consider them
A. Nitrogen has atomic number $7$, i.e. it has $7$ protons. When nitride ion is formed, one electron is gained. There is only change in net charge of the atom, no change in atomic number occurs.
B. This is also a similar case. There is no change in the atomic number or mass number.
C. Iron atoms have $26$ electrons while ferrous ion is the ion formed by losing two electrons from iron atoms. Thus it has only $24$ electrons. So there will be a difference in its electronic configuration.
D. Nuclear charge depends upon the protons, not the electrons. When chloride ion is formed, only electrons are gained. So it is the same in both chlorine atoms and chloride ions.
Thus the wrong statement is iron atoms, ferrous ions have the same electronic configuration.

Hence the correct option is C.

Note: An atom has neutral charge with equal number of positively charged protons and negatively charged electrons. When ions are formed, they have either extra electrons or missing electrons. When there is a missing electron, the atom has a positive charge. When there are extra electrons, the atom has a negative charge.