Question:
Three elements $X, Y$ and $Z$ are in the $3^{\text {rd }}$ period of the periodic table. The oxides of X, Y and Z, respectively, are basic, amphoteric and
acidic. The correct order of the atomic numbers of $X, Y$ and $Z$ is:
Correct Option: , 3
Solution:
When we are moving from left to right in a periodic table acidic character of oxides increases (as well as atomic number of atom increases)
$\therefore \quad \mathrm{X}<\mathrm{Y}<\mathrm{Z} \quad$ (acidic character)
$X