There are exactly 92 elements on Earth, all products of nature.
More have been created in laboratory 'atom smashers' and particle accelerators, but their atoms don't last long ... they fall apart. (That's why these elements are not found in nature ... the Earth is more than 4 billion years old, and those complicated atoms of elements higher than #92 fell apart before now.)
The main parts of the atom are:
-- the "nucleus", in the center, containing neutrons and protons; the number of protons is what determines what element it's an atom of
-- several electrons, whizzing around the nucleus, like planets in orbits, but so fast that you can never know exactly where any electron is; they form kind a fuzzy cloud all around the nucleus;
-- the electrons are far away from the nucleus, so the atom is mostly empty space; I've read that if the cloud of whizzing electrons were the size of Texas, then the nucleus in the center would be the size of a bunch of grapes !
-- most of the time, there are the same number of electrons as the number of protons in the nucleus, but not always; it's fairly easy for electrons to get pulled away from an atom atom, or to temporarily hook up with an atom where it doesn't really belong; one situation where this happens this happens is when there's an electric current flowing in the substance ... a lot of electrons are drifting from one atom to another, generally in the direction of the positive terminal of the battery. For example: If there's 1 Ampere of current flowing through a piece of wire, then there are about 6,250,000,000,000,000,000 electrons flowing into one end of the wire and out the other end, every second.
For an object moving at a constant acceleration, we would expect to see a position graph with a curved shape and a velocity graph with a straight shape.
