$A$ cuboidal container is filled with $20 \ L$ of water. If the length of the container is $30 \ cm$ and the width is $25 \ cm$,then the height will be ..... $dm$.

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 ....

Define Mass and Weight.

State the $SI$ unit of thermodynamic temperature and provide an explanation for this unit.

$81.4 \ g$ sample of ethyl alcohol contains $0.002 \ g$ of water. The amount of pure ethyl alcohol in $g$ to the proper number of significant figures is:

Perform the following calculations for the given exponential numbers:
$(i)$ $(6.7 \times 10^4) \times (8.4 \times 10^7)$
$(ii)$ $\frac{(3.4 \times 10^{-3})}{(6.5 \times 10^{-7})}$