Some substances are made of only one kind of atom. Other substances are made of more than one kind of atom. How are the properties of these two substances different

How does velocity and mass affect momentum?

Two friends at different locations want to communicate with each other by sending low energy signals. which of the following methods can they use to communicate? a) produce x-rays using colliding electrons and send them to radios, which capture sound b) send messages using infrared radiation, which travel in the form of waves c) send radio waves through intervening media like radio and television d) produce sound waves using microwaves from heated objects

2. how is heavy water different from normal water