basic chemistry review bio 103 final

bio 103 final basic chem review

what are the six elements that make up 95% of the body weight of organisms

carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur.

What is the atomic number of an element equal to

the number of protons in the atom

what is the mass number of an atom equal to

the total number of protons and neutrons in the atom

how many electrons can the first energy shell hold

2 electrons

what is the maximum number of electrons that each additional shell after the first can hold

8 electrons

what is the outermost energy shell of an atom called

valence shell

according to the octet rule, how many electrons should be in the outermost shell for it to be most stable

8 electrons

what is a molecule

two or more of the same type of atoms bonded together

what type of bond forms when electrons are transferred from one atom to another

ionic bond

what type of bond results when two atoms share electons equally

nonpolar covalent bond

what is electronegativity

the ability of an atom to attract electrons towards itself in a chemical bond

what makes water a polar molecule

the oxygen atom is more electronegative than the hydrogen atoms

what is a hydrogen bond

a weak attraction between a slightly positive hydrogen atom and a slightly negative atom

what is cohesion

the ability of water molecules to cling to each other

what is adhesion

the ability of water molecules to cling to other polar surfaces

what is the pH of a neutral solution

7

what is the pH of human blood

7.4

what condition results if blood pH drops below 7.0

Acidosis

what is a buffer

a chemical that keeps pH within normal limits

how much more acidic is a pH of 4 compared to a pH of 5

10 times