A sigma bond is cylindrically symmetrical about the bond axis. B. A pi bond is not symmetrical about the bond axis. C. The two molecular orbitals formed by mixing of the 1s orbitals of a pair of hydrogen atoms are both lower in energy than the atomic orbitals from which they are formed. D. A pi bond may be f

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? ?

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.