As we go from species to kingdom in a taxonomic hierarchy,the number of common characteristics

Pepsin is inactivated at $pH$

As the mass number $A$ increases,which of the following quantities related to the nucleus does not change?

The plates of a parallel plate capacitor are charged up to $100 \, V$. $A$ $2 \, mm$ thick dielectric plate is inserted between the plates. To maintain the same potential difference,the distance between the capacitor plates is increased by $1.6 \, mm$. The dielectric constant of the plate is:

$A$ man is standing on a balance and his weight is measured. If he takes a step in the left side,then his weight

Equimolar solutions of the following were prepared in water separately. Which one of the solutions will record the highest $pH$?