The shielding of electrons gives rise to an effective nuclear charge, zeff, which explains why boron is larger than oxygen. estimate the approximate zeff felt by a valence electron of boron and oxygen, respectively? a. +5 and +8b. +3 and +6c. +5 and +6d. +3 and +8e. +1 and +4

What happens when chlorine reacts with bromine? a. electrons move from the chlorine atoms to the bromine atoms. b. electrons move from the bromine atoms to the chlorine atoms. c. electrons are shared between the chlorine atoms and the bromine atoms. d. electrons become delocalized among the atoms.

Brutus, the dog, is pulling a bone to the left with a force of 20 n. lassie, another dog, is pulling a bone to the right with a force of 18n. what is the net force? a. b. c.

Which of the following is a characteristic shared by both electron and light microscopes? a. they both employ the use of objective lenses. b. both microscopes require an internal camera to visualize the specimen. c. both microscopes have a resolving power of 0.01 nm. d. they both utilize white light to magnify the specimen.