Choose the acidic oxide from the following.

$A$ solid element $Y$ conducts electricity and forms two types of chlorides: $YCl_n$ (a colorless volatile liquid) and $YCl_{n-2}$ (a colorless solid). To which group does element $Y$ belong?

$A$ $1 \ L$ flask is full of brown bromine vapour. The intensity of the brown colour of the vapour will not decrease appreciably on adding which of the following to the flask?

Two statements are given below.
Statement $I$: $SnF_4$ and $PbF_4$ are ionic in nature.
Statement $II$: $GeCl_2$ is more stable than $GeCl_4$.
The correct answer is:

Which of the following halides is least stable and has doubtful existence?

Lead is present in maximum quantity in which of the following types of glass?