Lithium contains two isotopes: Lithium-6 and Lithium-7. Lithium-6
makes up 7.5% of the world's total
lithium, while Lithium-7 makes up
92.5%. Calculate its average atomic
mass.

Compare and contrast physical changes with chemical changes.

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.

Alice did an experiment to find the relationship between the angle at which a ray of light strikes a mirror and the angle at which the mirror reflects the light. she placed a ray box in front of a mirror. she changed the angle at which the light from the ray box struck the mirror and noted the corresponding angle at which the mirror reflected the light. which of the following is the dependent variable in this experiment? the mirror used to reflect the light the ray box used as the source of light angle at which the light from the ray box strikes the mirror angle at which the mirror reflects the light from the ray box