What is the idea behind the law of multiple proportions?

Which is not true about oxygen-17 and oxygen-18?

James is trying to prove newton's 2nd law of motion. he tries to move four different objects with different masses, shapes, and sizes from point a to point b. the objects are a toy car, a car, a refrigerator, and a kitchen table. after some experimentation, he finds that force is dependent on the mass of the object, rather than it's size or shape. the object that takes the most force to move is the

What are similarities and differences between refraction, reflection, diffraction and absorption?