What is the atomic mass of an atom that contains 21 protons, 21 electrons, and 25 neutrons

Harry lives in a city, and he has a lung condition known as asthma. on certain days, harry has to stay inside because pollutants in the air make it difficult for him to breathe. which of these pollution sources are nonpoint sources that might bother harry if he goes outside? choose the two that apply.

Which of the following is not an assumption that scientists must make about the natural world? a. regularity b. causality c. predictability d. plausibility

Movement that is like a t a type of wave that transfers energy where the particles in the medium move in a circle motion while the energy travels left or right. a type of wave that transfers energy where the particles in the medium move perpendicular to the direction in which the energy is traveling. transfers energy from one location to another a type of wave that transfers energy where the particles in the medium move parallel to the direction in which the energy is traveling. movement that is back and forth, like an equal sign = 1. wave 2. parallel movement 3. perpendicular movement 4. transverse wave 5. longitudinal wave 6. surface wave