What do scientists use molecular clocks to estimate?

a. the age of fossilized remains found in an archeological dig.

b how long it will take for a molecule to break down into individual atoms

c how long ago various groups of organisms diverged evolutionarily from one another

d the rate at which a chemical reaction will occur at a given temperature and pressure

If 34.2 grams of lithium react with excess water, how many liters of hydrogen gas can be produced at 299 kelvin and 1.21 atmospheres? 2 li (s) + 2 h2o (l) yields 2 lioh (aq) + h2 (g)

Why is the bond angle in a water molecule less than the bond angle of methane? a. the central oxygen atom in water has two lone pairs of electrons, whereas the central carbon atom in methane has no lone pairs. b. the central hydrogen atom in water has one lone pair of electrons, whereas the central carbon atom in methane has two lone pairs. c. the central oxygen atom in water has four lone pairs of electrons, whereas the central carbon atom in methane has only one lone pair. d. the central oxygen atom exerts more repulsive force on surrounding atoms than the central carbon atom in methane does. reset next

Nan element’s square on the periodic table, the number with the greatest numerical value represents the