An igneous rock originally has 4 grams of uranium-238 in it. when dated, the rock only contains 2.4
grams. what are the parent and daughter concentrations (in percentages) and what is its age?

#7 how does the structure of amino acids allow them to form a polypeptide? each amino acid has an amino group and a carboxyl group. each amino acid has a hydrogen atom and a carboxyl group. each amino acid has a carboxyl group and an r group. each amino acid has an r group and a hydrogen atom.

The semi-conductors on the periodic table are classified as

Is water wet? my friends are debating.