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 +8
B. +3 and +6
C. +5 and +6
D. +3 and +8
E. +1 and +4

How many moles of water are created if 3 moles of hydrogen react completely with excess oxygen?

Which statement justifies that hydrogen peroxide (h2o2) is a polar molecule? the o – h bond is nonpolar and the molecule is asymmetric. the o – h bond is nonpolar and the molecule is symmetric. the o – h bond is polar and the molecule is asymmetric. the o – h bond is polar and the molecule is symmetric.

Which statement explains which component is likely to be more powerful in explaining a scientific phenomenon? a) component c, because a theory is often passed on possibility and not certainty b) component d, because a hypothesis is often based on possibility not certainty c) component c, because the ability to explain several occurrences in the natural world is a characteristic of a hypothesis d) component d, because the ability to explain several occurrences in the natural world is a characteristic of a theory