Question

An increase in temperature causes the mercury to move up the thermometer.

Why does this happen

Answer 1

$\mathfrak{\huge{\green{\underline{\underline{ANSWER :}}}}}$

The mercury pools in the bulb, but when it heats up, it expands. Because it can't expand through the bottom of the bulb, it is forced up the tube. That expansion, caused by the atoms flying around faster and taking up more space, is what makes the thermometer work.

Hope It Will Help.❤

Answer 2

A rise in temperature means a rise in energy, including for the mercury in a thermometer. ... So when you measure the temperature of something, it transfers heat to the glass of the thermometer (which expands slightly) which transfers heat to the mercury in the thermometer (which expands a lot)

Hope it helps