I need help with these questions

Find the mass in grams of 1.37x1020 particles of h3po4

56.16 gregor mendel was the first scientist to use statistics to analyze scientific data. before mendel's experiments, scientists believed that organisms acquired traits from their environment and passed them on to their offspring. after mendel's discoveries were accepted, scientists realized that traits passed to offspring were the result of genes being passed from parents to offspring. this is an example of pls

Which explanation is true about what happens to a ray of light when it strikes a mirror? a. a light ray is transmitted toward a mirror at a certain angle. the light ray is then reflected by the mirror at an equal angle but in the opposite direction of the transmitted ray. b. an incident ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then reflected at an angle equal to the angle of incidence but on the opposite side of the perpendicular line. c. a reflecting ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then refracted at an angle equal to the angle of the reflecting ray and on the same side of the perpendicular line. d. an incident ray strikes a mirror at an angle with a line parallel to the mirror. the light ray is then transmitted at an angle equal to the angle of incidence but on the opposite side of the parallel line. you so much! : -d take the time to try and answer correctly.