Why Mg and Ca, both form strong bases on reacting with water?

Great amounts of electromagnetic energy from our sun and other bodies in space travel through space. which is a logical conclusion about these electromagnetic waves? their energy must be very their frequency must be very low these waves can travel without a medium they only travel through a vacuum of space

Light waves can move through , but they travel fastest when they move through a(n) .

Which diagram represents the phase tha occurs after a solid melts?