Please Please answer this. What do these two changes have in common? - melting wax
- rain forming in a cloud

Both are only physical changes
Both are chemical changes
both are caused by heating
both are caused by cooling

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? ?

it is the most commonly accepted one

a electronegativity decreases beacuse the size of nucleus is bigger.