The increase in atmospheric carbon dioxide 3.5 billion years ago would have likely been contributed to by a) early cells undergoing anaerobic lactic acid fermentation. b)early cells using hydrogen sulfide in the formation of biomolecules. c)early cells beginning the process of photosynthesis and producing sugars. d)increasing colonies of cyanobacteria undergoing photosynthesis.

The answer is B. This is stipulated in the theory of abiogenesis. The atmosphere in early earth was composed of compounds such as methane, hydrogen sulfide, and ammonia. This reducing environment was right for the formation of biomolecules . This early life is similar to that found in hydrothermal vents deep in the oceans, today.

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.

c. live where it’s cold and icy