BIOL 190 Lecture Notes - Lecture 5: Covalent Bond, Hydrogen Bond, Atomic Number
Document Summary
Anything that occupies space and has mass. Calcium, phosphorous, potassium, sulfur, sodium, chlorine, magnesium. Compounds have different characteristics than its elements. Smallest unit of matter that still retains the properties of an element. Mass number = # of protons and neutrons. Mass # - atomic # = # of neutrons. Atomic # = # of electrons (-) All have c (carbon) and h (hydrogen) Atoms combine to obtain a full outer orbital. Stable (happy) 8 electrons (except 2 for hydrogen) Atoms can gain, lose, or share electrons (whatever it takes to get to a stable state) Covalent bond- atoms bonds by sharing electrons. Polar molecule- opposite charges on opposite ends of molecule. Electrons aren"t shared equally- the negatively charged electrons spend more time around one atom (the oxygen atom in water) Ions- atoms with a positive or negative charge. Examples: na has one electron in the outer shell. Important to the properties of water (electrons are not moving between molecules)
