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).
y-axis â(plural y-axes) ( 1 algebraic geometry) The axis on a graph that is usually drawn from bottom to top and usually shows the range of values of variable dependent on one other variable, or the second of two independent variables.  Finnish: y-akseli (fi)