Which device is used in submarines to see objects above the water surface without surfacing?

Which everyday phenomenon explains why a ship made of steel can float despite steel being denser than water?

Which process in the water cycle involves the sun's energy turning liquid water into water vapour?

Which type of wave requires a material medium to travel and cannot propagate through vacuum?

Which part of the water cycle involves water vapour cooling and turning back into liquid water droplets to form clouds?

Which gas is produced during electrolysis of water at the negative electrode called the cathode?

Which part of the water cycle involves water falling from clouds back to the Earth's surface as rain snow or hail?

Which gas is produced during the electrolysis of water at the positive electrode called the anode?

Which everyday item uses a bimetallic strip that bends when heated to control temperature in older thermostats?

Which naturally occurring radioactive element was discovered by Marie Curie and named after her home country?

Which everyday principle explains how blood pressure monitors measure pressure in the arteries?