Which is true about a gas? Choose the correct answer. Responses It changes to a liquid when it heats up. It changes to a liquid when it heats up. It takes up a definite amount of space. It takes up a definite amount of space. It takes up a definite amount of space but does not have a definite shape. It takes up a definite amount of space but does not have a definite shape. It does not take up a definite amount of space and does not have a definite shape. It does not take up a definite amount of space and does not have a definite shape.