Explain the importance of the periodic table​

In fact, the periodic table is so accurate that it allows scientists to predict the chemical and physical properties of elements that hadn't yet been discovered. ... "The elements, if arranged according to their atomic weights, exhibit an apparent periodicity of properties," said Mendeleev.

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?