2nd quarter science

• atom - basic unit of matter
• proton, neutron, electron - 3 types of subatomic particles
• proton - positively charged
• neutron - neutrally charged
• electron - negatively charged
• atomic theory - scientific concept that explains the nature of matter
• atomos - means uncuttable
• atomism - democritus, matter is made up of tiny indivisible particles called atoms
• solid sphere model - john dalton, atoms are indestructable spheres
• joseph john thomson - full name of jj thomson
• plum pudding model - jj thomson, negatively charged particles
• nuclear model - ernest rutherford, gold foil experiment electrons are orbiting
• planetary model - neils bohr, like planets in the solar system
• electron cloud model - erwin schrodinger electrons is a wave
• gilbert lewis - introduced the theory of shared electron pairs
• lewis electron dot structure - one dot to represent each valence electron
• octet rule - eight electrons in order to become stable
• ionic bond - valence electron of an atom is transferred to another atom
• covalent compound - non metal + non metal consists of neutral molecules
• non polar molecules - two identical non metallic atoms
• polar molecules - two different non metallic atoms
• electromagnetivity - measures the ability of an atom to attract electrons
• multiple bonds - more than 1 pair of electrons
• metallic bonding - entirely metal
• alloys - mixture of two or more elements but atleast one metal