質問: bsc2010 bsc2010 bsc2010 bsc2010
回答: 2.1 atoms: living and nonliving things are composed of atoms neutrons-neutral protons-positive electrons-negative dalton- mass of one proton or neutron 1.7*10-24 most atoms are neutral because the number of electrons cancel out the number of protons moleculardetective.org mass spectrometer: how to measure atoms and molecules relearn the periodic table, atomic number-number of protons living things are composed of o,c,h,p,n,s electrical neutrality- #protons=#electrons niels bohr-the bohr model; model of atomic structure n- shell # 1st shell- 2 max 2nd shell-8 max 3rd shell- 18 max atoms unfilled outer shells tend to undergo chemical reactions octet rule-stoma with at least 2 electron shells form stable molecules so they have at