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

Which of the following is correct?

Pressure is determined as force per unit area of the surface. The $SI$ unit of pressure, Pascal is as shown below:
$1 \, Pa = 1 \, N \, m^{-2}$
If mass of air at sea level is $1034 \, g \, cm^{-2}$, calculate the pressure in Pascal.

Convert the following pressure values into atmosphere $(atm)$:
$(a)$ $735 \ torr$
$(b)$ $985 \ mbar$
$(c)$ $1.42 \times 10^5 \ Nm^{-2}$

Choose the correct statements.
$A$. Weight of a substance is the amount of matter present in it.
$B$. Mass is the force exerted by gravity on an object.
$C$. Volume is the amount of space occupied by a substance.
$D$. Temperatures below $0^{\circ} C$ are possible in Celsius scale,but in Kelvin scale negative temperature is not possible.
$E$. Precision refers to the closeness of various measurements for the same quantity.

Identify the carrier gas commonly used in gas chromatography.