The density of the solution is $2.15 \ g \ mL^{-1}$,then the mass of $2.5 \ mL$ solution in correct significant figures is $........ \ g$.

Which prefix used in the $SI$ system has a multiplier of $10^{-6}$?

Fill in the blanks given below:
$(i)$ The symbol for the quantity of luminous intensity is .......... and the name of its $SI$ unit is ......... .
$(ii)$ The prefixes used for $10^{-18}$ and $10^{18}$ are ............ and ........... respectively.
$(iii)$ The $SI$ unit of density is ......... .
$(iv)$ In the ........ unit of temperature,its negative value is not possible.

$A$ student performs a titration with different burettes and finds titre values of $25.2 \ mL$,$25.25 \ mL$ and $25.0 \ mL$. The number of significant figures in the average titre value is

Which of the following has the highest energy value?

Given the numbers: $161 \ cm, 0.161 \ cm, 0.0161 \ cm$. The number of significant figures for the three numbers are