Asample of a material has 200 radioactive particles in it today. your great-grandmother measured 400 radioactive particles in it 100 years ago. 100 years from today, how many radioactive particles will the sample have?

Sawyer is studying diffraction. he draws a diagram of a plane wave to show how light waves travel. which best describes sawyer’s error? the wave fronts should be perpendicular to the direction in which the waves move. the arrow showing the direction of movement of the waves should be pointing to the left. the arrow showing the direction of movement of the waves should be pointing downward. the wave fronts should be both parallel and perpendicular to the direction in which the waves move.