$x$ grams of calcium carbonate was completely burnt in air. The weight of the solid residue formed is $28 \text{ g}$. What is the value of $x$ (in grams)?

Two magnets are held together in a vibration magnetometer and are allowed to oscillate in the earth's magnetic field. With like poles together,$12$ oscillations per minute are made,but for unlike poles together,only $4$ oscillations per minute are executed. The ratio of their magnetic moments is:

The radius of ${}_{52}Te^{125}$ nucleus is $6 \text{ fermi}$. The radius of ${}_{13}Al^{27}$ nucleus in meters is

Heterogametic male condition does not occur in

Which one of the following conditions correctly describes the manner of determining the sex?

Among the following compounds,which is planar in shape?