What is the charge positive or negative of the nucleus of every atom

What is the weight of a feather (mass = 0.0001 kg) that floats through earth's and the moon's atmospheres?

What is friction? how does it affect the motion of an object?

Which statement is the best definition of an atom? a) anything that has mass and occupies space. b) the smallest particle that has the properties of an element. c) a substance that cannot be broken down chemically into simpler substances. eliminate d) the smallest unit of a substance that exhibits all of the properties characteristic of that substance.