Unit A: 1.2 Matter is made of atoms Identify the smallest particles of matter How atoms combine into molecules How atoms and molecules move

Atoms The basic unit of matter All matter made of different types and arrangements of atoms Building blocks: atoms are the small parts that make up a larger structure. “Matter is not something that contains atoms. Matter IS atoms.”

Atoms Extremely small: take above shape – pretend an atom is blown up to this size, how large would the pin be? It’d cover 90 mi2 (1/7 the area of London; Catalina Island = 76 mi2), 80 miles high (15x Mt. Everest) Too small for a light microscope Spoonful of water contains 500,000,000,000,000,000,000,000 atoms How to find the mass of an atom? Find the mass of a large amount of a substance and divide it by the number of atoms to estimate the mass of one atom Add up mass of all atoms in the spoonful of water: m = 5g

(Unit B, Atomic Structure)

Mini-lab: How small is an atom? How small is an atom? How small is a cell? Investigate the world of the very small by cutting a 28 centimeter (11 inch) strip of paper in half as many times as you can. If you can cut the strip of paper in half 31 times you will end up with a piece of paper the size of an atom! MATERIALS 1 strip of paper 28 centimeters long (11" inches) 1 pair of scissors PROCEDURE Take your strip of paper and cut it into equal halves. Cut one of the remaining pieces of paper into equal halves. (# each cut 1, 2, 3, 4…) Continue to cut the strip into equal halves as many times as you can. Make all cuts parallel to the first one.

How far did we get? Some comparisons Cut 1 14.0 cm 5.5" (inches) Child's hand, pockets Cut 2 7.0 cm 2.75" Fingers, ears, toes Cut 3 3.5 cm 1.38" Watch, mushroom, eye Cut 4 1.75 cm .69" Keyboard keys, rings, insects Cut 6 .44 cm .17" Poppy seeds Cut 8 1 mm .04" Thread. Congratulations if your still in! Cut 10 .25 mm .01" Still cutting? Most have quit by now Cut 12 .06 mm .002" Microscopic range, human hair Cut 14 .015 mm .006" Width of paper, microchip components Cut 18 1 micron .0004" Water purification openings, bacteria Cut 19 .5 micron .000018" Visible light waves Cut 24 .015 micron .0000006" Electron microscope range, membranes Cut 31 .0001 micron .0000000045" The size of an Atom!

Is there anything smaller? Yes, an atom’s nucleus is ~41 cuts! Electrons are 9,000 times smaller than this! These things are far beyond the range of sensory perception, but not beyond the range of human understanding.

Molecules What makes up substances besides atoms and molecules? Atoms (or combinations of atoms, molecules) are the only matter in a substance…there is empty space between atoms but it is too small to see and has no mass When two or more atoms bond together Atoms can be the same or different Ex: water = 2 hydrogen atoms, 1 oxygen atom Ex: hydrogen gas = 2 hydrogen atoms Ex: Vitamin E = 29 Carbon, 50 H, 2 O Same atoms, different # = different substance Oxygen (2 O  O2) and Ozone (3 O  O3)

Particles + Particles = Atoms    Atoms + Atoms = Molecules    Molecules + Molecules = Matter

Motion of Atoms and Molecules Atoms and Molecules are constantly in motion colliding with other atoms and molecules Not as obvious with solids, but they are still moving… States of matter 1.4