How many seconds are there in $2$ days (in $s$)?

The temperature of $32^{\circ} C$ is equivalent to

Which of the following have the same number of significant figures?
$(A)$ $0.00253$
$(B)$ $1.0003$
$(C)$ $15.0$
$(D)$ $163$
Choose the correct answer from the options given below:

$81.4 \ g$ 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:

Write a note about The International System of Units $(SI)$.

The density of mercury is $13.6 \, g/cm^3$. Find the mass of $1 \, L$ of mercury. (in $, g$)