According to figure 12-2, what fraction of the original parent isotope still exist after 4 half-lives have passed

The phylogenetic tree illustrates the relationship between humans and our closest living relatives. the tree was based on biochemical comparisons, including dna and amino acid sequences. according to the biomolecular data, we could infer that

Which chemical equation is unbalanced? which chemical equation is unbalanced

What best explains the inability for life to exist in earth early atmosphere