A period on the periodic table is a horizontal row. The atoms in this row show a trend in their width, and in the amount of work needed to make them an ion, among the fe â¦ w other similarities.
A coordinate grid has two perpendicular lines, or axes, labeled like number lines. The horizontal axis is called the x-axis. The vertical axis is called the y-axis. The point where the x-axis and y-axis intersect is called the origin. The numbers on a coordinate grid are used to locate points. Each point can be identified by an ordered pair of numbers; that is, a number on the x-axis called an x-coordinate, and a number on the y-axis called a y-coordinate. Ordered pairs are written in parentheses (x-coordinate, y-coordinate).
The horizontal line is known as X-axis and the vertical line is known as Y-axis. The coordinate point (x, y) on the Cartesian plane says that the horizontal distance of the point from the origin is x, and the vertical distance is y. If the sign of x is positive the point is on the right of the origin, else it is on the left.