BIOL 1201 : Biology Exam 1
Document Summary
Atom: smallest unit into which an element can be divided: nucleus, proton (+1 charge, 1 dalton mass, neutron (0 charge, 1 dalton mass, electron (-1 charge, essentially without mass) Atomic number is determined by the number of protons in the nucleus. Atomic mass is the number (mass) of protons and neutrons in the nucleus. Electrical charge: number of electrons = number of protons: in an ion the number of protons doesn"t match the number of electrons, giving the atom a charge. Compound substance that can be broken don into two or more elements: e. g. water, table salt, etc. Chemical bonds- forces holding atoms together in compounds. What determines the number and type of chemical bonds: number = valence, type = electronegativity. Electronegativity- measure of the tendency of an atom to attract a bonding pair of electrons: the measure of attraction the atoms have for electrons.
