the atomic number in sodium is 11. how many protons neutrons and electrons are in a sodium ion with a charge of +1 and a mass number of 23

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

The formation of a solid, also known as a is an indication of a chemical change. precipitate particulate particle powder

Which part of earth’s surface receives the most direct rays from the sun? a) equator b) ocean c) poles d) mountains