I actually learned about this stuff about 3 years ago and this is what I can tell you what I remember and hopefully it helps in a way... [Newton’s law of motion] There’s unbalanced forces, friction, and balanced forces. Unbalanced forces is where the object (in this case the box) is moving in one direction because one of the forces is applying more pressure than the other Friction is where the box would be harder to push but if it’s still an unbalanced force, it will still move in one direction. The surfaces of the ground and or object isn’t smooth. Therefore creating difficulty when moving it. A Balanced force will not move the object in any direction. This is because there is an equal amount of force being applied to all opposing sides. The net force will always equal 0 when there’s a balanced force!
The number of electrons in the outermost shell of an atom determines its reactivity. Noble gases have low reactivity because they have full electron shells. Halogens are highly reactive because they readily gain an electron to fill their outermost shell.
