The smallest way to describe our Earth

Atoms  This is the smallest unit of an element having the same properties of that element  Arrangement and types of atoms give matter its properties

Atoms

Elements  Elements are a substance that can not be broken down into a simpler form  All the elements can be found on the periodic table.  There are 94 elements that are naturally occurring in nature. Hydrogen- plutonium. All the rest are man-made.

Elements  The elements after bismuth (element 83) the elements are not very stable and begin to decay

Periodic Table

Elements  A single atom of an element is made up of 3 basic parts: protons, neutrons, and electrons  Protons and Neutrons are concentrated in the middle of the atom  The electrons rotate around the atom

Atom

Elements  Protons are particles that have a postive electric charge  Neutrons are particles that have no electric charge (neutral)  Electrons are particles that have a negative electric charge

Mass and Atomic numbers  The atomic mass is equal to the sum of protons and neutrons in the nucleus of an atom  The atomic number is equal to the number of protons in the nucleus

Elements  In a neutral atom (an atom with a neutral charge) will have the same number of protons and electrons  In a neutral atom the number of neutrons can vary but unless specified differently will also be the same as protons.

Compounds  Compounds are substances that are made up of two or more elements chemically combined that cannot be separated physically  Compounds are held together by chemical bonds

Chemical Bonds  Chemical Bond- Foces that hold together the atoms that combine to make up a compound  Types of chemical bonds: Covalent bonds and ionic bonds

Types of Bonds  Ionic bonds are a combination of oppistely charged ions  Ions are electrically charged atoms  Atoms become ions by losing or gaining electrons  If an atom gains electrons it is negatively charged  If an atom loses electrons it is positively charged

Types of Bonds  Covalent bonds is the attraction of two atoms through a sharing of electrons.  Water is an example of a covalent bond

Mixing things up  Mixture is many different types of objects mixed together.  This is not a bond. These objects are just mixed together

Mixing things up  A type of mixture that deals with dissolving substances.  Ex. Salt water, coffee, Tea with sugar

Mixing things up  Heterogeneous mixture is a combination of materials that are easily recognizable.  Ex. Soil  Homogeneous mixtures are a combination of materials that are not easily recognizable.  Ex. Milk

Matter  As we have talked about before matter is anything that takes up space and has a mass  In other words, it has a volume and weighs something.

Matter  Matter has two different properties that you need to be able to distinguish between; physical and chemical properties

Physical Properties  Physical properties are those that you can observe without changing a substance into a new substance  Ex. Color, shape, odor, density

Chemical Properties  Chemical properties are those that descrbe how one substance changes when reacting with another substance  Ex. Rusting of Iron, burning of wood

4 States of Matter  There are four states of matter in which they can exist: solid, liquid, gas, and plasma  Each has its own way of forming the atoms of a certain substance

Solids  Solids are formed by atoms or molecules that are in a fixed position relative to each other  Atoms are molecules are strongly attracted to each other and resist being separated  Set Shape and set Volume

Types of Solids  Crystalline structures- have regular shapes and may cleave along well- defined surfaces  Glasses- They do not break along well defined surfaces. Shatter or break into lots of tiny pieces.

Liquids  Liquids is a type of matter where the atoms or molecules remain close to one another, but are fee to change positions with each other.  This allows liquid to flow as it takes the shape of its container  Set Volume but takes shape of container

Gases  Gases contain atoms or molecules that have very little attractive force on each other  Fill entire container no matter how large or small  NO set volume and No set shape

Plasma  This is matter heated to temperatures much higher than we normally see.  Plasmas are composed of ions and free electrons  You can find these in lightning bolts, florescent lights, and even stars