What is the process of a substance changing from a gas to a liquid called?

What type of celestial object is a rapidly rotating neutron star that emits beams of radiation, observed as periodic pulses?

Which of the following is a measure of the total amount of dissolved salts in water, often used to determine water salinity?

Which of the following is an example of a homogeneous mixture?

What is the force that opposes the motion of objects through a fluid (liquid or gas)?

What is the name of the massive cloud of gas and dust from which a star and its planets form?

What is the relationship between frequency (f) and wavelength (λ) in a wave?

Which of the following is a noble gas?

What is the function of the Eustachian tube in the human ear?

In the human reproductive system, what is the function of the testes in males?