The planet Gallifrey has 2 times the gravitational field strength and 2 times the radius of the Earth. How does the mass of the planet Gallifrey compare with the mass of Earth?

When fat comes in contact with sodium hydroxide, it produces soap and glycerin. determine whether this is a physical change or a chemical change. explain your answer

When you drop a pebble from height a it reaches the ground with speed v if there is no air resistance. from what height should you drop it so it will reach the ground with three times the speed? (a) 9m (b) 3m (c) 6m (d) 18m

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?