Planets 4 Billion Years Ago... II

Which one of the following is present today but was absent about 3.5 billion years ago ?

About 4.6 billion years ago, the Earth consisted of a solid ___ and a gaseous ____

Consider two nuclei of the same radioactive nucclide . One of the nuclei was created in a supernova explsion 5 billions year ago . The probability of decay during the next time is

Assertion. All organisms contain the same organic compounds in about the same proportions. Reason. All organisms have evolved from the first primitive cells which came into existence about 3.6 billion years ago.

Dominant flora, 200 million years ago was that of

Universe originated about 15 billion year ago by

The abiogenesis occurred about how many billion years ago