Which compound results from covalent
bonding?
NH4CI
K2S04
C6H1206
NACI

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.

this age may represent the age of the earth's accretion, of core formation, or of the material from which the earth formed. this dating is based on evidence from radiometric age-dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.