X, Y, and Z are the three elements in $3^{rd}$ a period of the periodic table. Oxides of X, Y, and Z are basic, amphoteric, and acidic. What will be its correct order in atomic number?

The correct option is A

$\mathrm{X}<\mathrm{Y}<\mathrm{Z}$

Explanation for the correct options

(A) $\mathrm{X}<\mathrm{Y}<\mathrm{Z}$

Atomic Number:

• The number of protons each element contains determines its atomic number, which is used to distinguish one element from another.
• The total number of protons and neutrons in an element determines its mass number.
• All of the elements in the contemporary periodic table have increasing atomic numbers, and as a result, increasing mass numbers.

Given Condition:

• Given, $\mathrm{X}$ is basic, $\mathrm{Y}$ is amphoteric and $\mathrm{Z}$ is acidic.
• $\mathrm{X}<\mathrm{Y}<\mathrm{Z}$ (atomic number).

Final Answer: Hence option (A) is correct, $\mathrm{X}<\mathrm{Y}<\mathrm{Z}$.