Hydrogen is by far the most abundant element in the universe. It makes up about 93 percent of all atoms in the universe and about three-quarters of the total mass of the universe. Hydrogen occurs both within stars and in the interstellar space (the space between stars).
It is an imaginary line from the Earth's north pole to its south pole, passing through the center of the Earth. Imaginary in the sense that it is not marked in any way; howeve â¦ r, Earth rotates around this axis.
Definition: The vertical and horizontal lines that make up the quadrants of a coordinate plane. The vertical axis is usally referred to as the y axis and the horizontal axis is usually referred to as the x axis. Pronunciation: axiz.