Why does carbon form four covalent bonds? A)Because carbon has a high electronegativity .B)Because carbon needs four electrons to fill its outer shell. C)Because the most common isotope has four neutrons. D)Because carbon tends to give up four electrons to balance the charge of its protons. E)Because carbon has a low electronegativity.

For which of the following organelles are the structure and function correctly described?A) Endoplasmic reticulum—a network of interconnected membranes forming sacs and canals that makes and packages protein molecules for secretionB) Ribosomes—membranous vesicles containing digestive enzymesC) Golgi apparatus—particles, composed of protein and RNA, which synthesize proteinsD) Mitochondrion—non-membranous structure that synthesizes proteins

 How is a polymer formed from multiple monomers?a. From the growth of the chain of carbon atomsb. By the removal of an —OH group and a hydrogen atomc. By the addition of an —OH group and a hydrogen atomd. Through hydrogen bonding

What is generally the range of a star’s hydrogen burning lifetime?

Stars to the upper right of the Hertzsprung-Russell diagram tend to be relatively

Our local group is composed of how many galaxies?

What determines if a star becomes a white dwarf, a neutron star, or a black hole?

The changing shapes of constellations in the night sky is caused by

Light bends when it

The background stars during a solar eclipse are those of constellations