$A$ 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

Convert the following into basic $SI$ units:
$(i)$ $28.7 \, pm$
$(ii)$ $15.15 \, pm$
$(iii)$ $25365 \, mg$

Fill in the blanks given below:
$(i)$ At ........ ${\,^\circ }{\text{C}}$,the values of temperature in both ${\,^\circ }{\text{C}}$ and ${\,^\circ }{\text{F}}$ are equal.
$(ii)$ The number of significant figures in $0.03$ is .....
$(iii)$ The closeness of various measurements for the same quantity is called .........
$(iv)$ The agreement of a particular value to the true value of the result is called ....

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

If the speed of light is $3.0 \times 10^8 \ ms^{-1}$,calculate the distance covered by light in $2.00 \ ns$. (in $m$)

Which smaller units of $kg$ are used to measure the mass of chemicals with very low mass?