Carbon-12 is the most common isotope of carbon. it has 6 protons, 6 neutrons, and 6 electrons. or it's 6 electrons, 4 are valence electrons. how many covalent bonds can a carbon atom form?

Describe the iron sulfide hypothesis and the lipid membrane hypothesis.

Which muscle is responsible for inhalation ?

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