Final answer:
The zig-zag line on the periodic table separates metals from non-metals and helps predict certain properties of the elements. Metals are found on the left side of the line, while non-metals are on the right side.
Step-by-step explanation:
The zig-zag line on the periodic table helps indicate properties of elements by separating metals from non-metals. Metals are found on the left side of the line, while non-metals are on the right side. Along the line, you find metalloids which exhibit properties intermediate between metals and non-metals.
One of the reasons the zig-zag line is useful is because it helps predict certain properties of the elements. For example, metals tend to have a shiny appearance, are good conductors of heat and electricity, and are malleable and ductile, while non-metals are generally dull, poor conductors, and brittle. By knowing the position of an element in relation to the zig-zag line, you can make predictions about its properties.
For instance, elements to the left of the zig-zag line tend to have lower ionization energies and smaller atomic radii, while elements to the right have higher ionization energies and larger atomic radii. This trend can be observed across a row or period in the periodic table.