Could someone help me answer this?

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

Which is the correct symbol for an isotope of iodine with 53 protons and 78 neutrons?

The law of the conservation of momentum says that the total momentum of any closed and isolated system cannot