The Basics of Science Why does it matter?

Matter  Anything that takes up space and has mass

Atom  The basic unit of matter  The smallest particle of an element having the chemical properties of the element

Elements  A substance made up of only one type of matter –See Periodic Table of Elements

Molecules  The result of two or more atoms combining by chemical bonding. –you cannot break it into smaller pieces and keep the same properties  Examples –H2O–H2O–H2O–H2O –CO 2 –NaCl

Subatomic Particles  Protons –Have a positive charge (+) –Part of Nucleus  Neutrons –Have a neutral charge (O) –Part of the Nucleus  Electrons –Have a negative charge (-) –“float” around the Nucleus

Mass  How much “stuff” (matter) there is in an object  We use a Balance to find Mass –Triple Beam Balance

Volume  How much space something takes up –If it is regular shape you can use mathematical formula  Length x Width x Height –If it is irregular, you can use the displacement of water to tell the volume of the shape  Example in beaker

States of Matter Solid  highly compacted molecules, definite shape, definite volume, definite mass. liquid  molecules are more spread out, does NOT have a definite shape (it takes the shape of its container), definite volume, definite mass Gas  molecules are really spread out, does NOT have a definite shape (takes the shape of its container), does NOT have a definite volume.

Density  The amount of matter in a given space. (Mass per unit volume)  Compares mass to volume

If the mass stays the same…  If the mass stays the same, but volume decreases, then density increases. –Same amount of stuff into smaller area  If the mass stays the same, but volume increases, then density decreases. –Same amount of stuff into larger area

If volume stays the same..  If the volume stays the same, but mass decreases, then density decreases. –Less stuff in the same amount of space  If the volume stays the same, but mass increases, then density increases. –More stuff in the same amount of space

Why should I care about Density?  If an object’s density is HIGHER/ MORE THAN another object’s density then it will sink/fall/ go down under  If an object’s density is LOWER/ LESS THAN another object’s density, then it will float/rise/ go up above