Aluminum is an element. Which best describes what makes up a sample of aluminum?
one kind of atom
O two different kinds of atoms
all carbon-based atoms
a carbon atom and non-carbon atoms

Compare the depth of field when focusing with low power and high power. which power has the greater depth of field?

How can a geological time scale best be reconstructed? a) comparing vestigial structures in living species b) comparing homologous structures in living species c) examining homologous structures in fossil remains d) examining the written records of scientists from past cultures

The first amino acid of a new polypeptide chain is