Which set of elements has the most similar physical and chemical properties? H
Li/Be
Na/Mg
K/ Ca
Rb/Sr
Cs/Ba
Fr/Ra

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? ?

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error