What is the name of the process where a solid changes directly to gas?

Which property of a magnet means it will always realign itself to point in a north-south direction if freely suspended?

Which atmospheric phenomenon causes the sky to appear blue during the day?

Which common observation explains why sound seems louder when heard through walls compared to open air over long distances?

Which kidney process selectively returns useful substances like glucose back to the bloodstream?

Which instrument is used to detect and measure the magnitude of earthquakes?

Which animal group lacks a backbone and includes insects worms and molluscs?

Which gas is released when metals like zinc react with dilute hydrochloric acid?

Which vitamin acts as an antioxidant protecting cells from damage and is found in nuts and seeds?

Which vitamin deficiency causes pellagra characterised by dermatitis diarrhoea and dementia?

Which gas law states that the volume of a gas is directly proportional to its temperature at constant pressure?