Briefly explain why it is difficult to determine the age of our planet.

It is difficult to determine the age of our planet because the time this accretion process took is not yet known and predictions from different accretion models range from a few million up to about 100 million years

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds