help! help! plz Describe simple experiments in support of the following. i) Electrons travel in straight lines. ii) Electron are negatively charged. iii) Electron have mass and energy. ​

Enzymes affect the reactions in living cells by changing the

13. a covalent bond between two atoms is likely to be polar if: a. one of the atoms is much more electronegative than the other. b. the two atoms are equally electronegative. c. the two atoms are of the same element. d. the bond is part of a tetrahedrally shaped molecule. e. one atom is an anion.

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.