Explain the differences between mass and weight, list instruments to measure temperature, and state reasons why water is not used as a thermometric liquid.

Here are the answers to question 2:

a) Four differences between Mass and Weight:

Feature	Mass	Weight
Definition	A measure of the amount of matter in an object.	The force exerted by gravity on an object.
Unit	Measured in kilograms (kg).	Measured in Newtons (N).
Nature	It is a scalar quantity.	It is a vector quantity.
Variation	It remains constant regardless of location.	It varies with the strength of gravity (location).

b) Four reliable instruments for measuring the temperature of a body are:

• Clinical thermometer
• Laboratory thermometer
• Resistance thermometer
• Thermocouple

c) Three reasons why water is NOT used as a thermometric liquid:

• Water exhibits anomalous expansion between $0^\circ\text{C}$ and $4^\circ\text{C}$, meaning it does not expand uniformly with temperature.
• It has a high specific heat capacity, which makes it slow to respond to temperature changes.
• Water has a relatively high freezing point ($0^\circ\text{C}$) and a low boiling point ($100^\circ\text{C}$), limiting its range of use.

d) Two reasons why alcohol is used as a thermometric liquid:

• Alcohol has a very low freezing point (e.g., ethanol freezes at $-114^\circ\text{C}$), making it suitable for measuring very low temperatures.
• It has a high coefficient of expansion, meaning it expands significantly for a small change in temperature, making it sensitive.