1.Why did you use a pencil to mark the paper and not a pen? 2.Why do you have to use a different capillary tube for each sample? 3.Why is it very important in the amino acid chromatogram not to touch the paper with your fingers or hands? 4.If two samples have identical Rf values does this mean that they are necessarily identical molecules? Explain 5.What is your unknown? How do you know?

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.

label a cell membrane

label b cytoplasm

label c ribosomes

label d dna

the membrane forms the outside of the cell

cytoplasm is the liquid within

ribosomes are the components within that distribute rna

the dna is the genetic make-up