Classification ...

Electronic configuration of $Si$ in ground state is _____________.

Which of the following sets does not belong to the same group?

What are the electronic configuration of $Na^{+}$ and $Cl^{-}$ ions?

Which element of 2nd period forms most acidic oxide?

The electronic configuration of a dipositive metal ion $M^{2+}$ is $2, 8, 14$ and its ionic weight is $56$. The number of neutrons in its nucleus would be:

Who was the first to classify the elements into metals and non-metals?

Which is the correct electronic configuration of $Cr$(Chromium)?

Which of the following is correct for electron affinity?

The correct order of electron affinities of $S,\ N,\ O$ and $Cl$ is:

Number of electrons in $M$ shell of an element with atomic number $28$ is _______.