Which of these liquids is commonly used in household liquid-in-glass thermometers?

• cooking oil
• ethanol (colored)
• liquid nitrogen

The thermometer is placed in a container filled with pure melting ice. State the temperature of this melting ice.

A Celsius thermometer is defined using two standard fixed points. State the numerical temperatures of these two fixed points.

• lower fixed point = $\dots \dots \dots \dots \dots \dots \dots$ ${}^{\circ }C$
• upper fixed point = $\dots \dots \dots \dots \dots \dots \dots$ ${}^{\circ }C$

The sentences below describe thermal processes.

Complete each sentence using one of the words from the box. Each word may be used once, more than once, or not at all.

• Double-glazed windows help keep a house warm because the trapped air between the glass panes acts as a good thermal $\dots \dots \dots \dots \dots \dots \dots$.
• In metals, thermal energy is transferred extremely quickly mainly by $\dots \dots \dots \dots \dots \dots \dots$.
• A hot air balloon rises because the heated air inside expands, becomes less dense, and moves upwards; this is transfer of energy by $\dots \dots \dots \dots \dots \dots \dots$.
• A cold drink stays cool longer when stored in a container with a silvered outer surface because silver is a good $\dots \dots \dots \dots \dots \dots \dots$ of thermal radiation.