Which phrase describes a compound that consists of two elements? (1) a mixture in which the elements are in a variable proportion (2) a mixture in which the elements are in a fixed proportion (3) a substance in which the elements are chemically combined in a variable proportion (4) a substance in which the elements are chemically combined in a fixed proportion

How are elements arranged in a periodic table

Why does his teacher ask him to balance the equation by including the correct coefficient

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.