Classifying Matter: Elements, Compounds, and Mixtures
What is Matter? Anything that has mass and takes up space (volume) What is the only thing that is NOT matter? All matter is made up of particles: Atoms Molecules ENERGY
Atoms Atoms are basic building blocks of matter that make up everyday objects. Made of subatomic particles: Protons Neutrons Electrons
Protons They are positively charged. Are located in the nucleus. Have a mass of 1 amu Amu= atomic mass unit In this picture, the protons are the blue pieces in the center of the atom.
Neutrons Neutrons are neither positive nor negative. Neutrons are in the nucleus of an atom. Have a mass of 1 amu Amu= atomic mass unit In this picture, neutrons are the purple pieces in the center of the atom.
Electrons Electrons orbit around an atom. In this picture, they are the small yellow bits. They have a negative charge. They are lighter than protons or neutrons. Have “no” mass Too small of an amount to count
Molecules A molecule is the smallest particle of a substance that exists alone. This is a picture of a water molecule. It is two parts hydrogen and one part oxygen.
Pure Substances A sample of matter that has definite chemical composition Definite physical & chemical properties
Elements Pure substance that cannot be separated into simpler substance by physical or chemical means.
An element is a substance made up of only one kind of atom. Elements make up all substances on the earth. Abbreviated with symbols on the periodic table Elements
Compounds A substance composed of all the same molecule A compound is two or more elements combined together. This is a picture of a salt compound.
Compounds Pure substance composed of two or more different elements joined by chemical bonds. Made of elements in a specific ratio that is always the same Has a chemical formula Can only be separated by chemical means, not physically
Chemical Formula Shows the number of atoms of each element bonded together in the molecule. Letters = Elements Subscripts = come after the atom type they are counting Large numbers before tell how many molecules
Pure Substance: ELEMENTS:COMPOUNDS:
Mixtures A combination of two or more pure substances that are not chemically combined. substances held together by physical forces, not chemical No chemical change takes place Each item retains its properties in the mixture They can be separated physically Chem4kids.com
ELEMENTS: COMPOUNDS: MIXTURES:
Mixtures vs. Compounds
Can you identify the following? You will be shown a series of photos. Tell if each photo represents an item composed of an element, compound, or mixture. Review: An element contains just one type of atom. A compound contains two or more different atoms joined together. A mixture contains two or more different substances that are only physically joined together, not chemically. A mixture can contain both elements and compounds.
Element, Compound, or Mixture? Rocks
Element, Compound, or Mixture? Rocks
Element, Compound, or Mixture? Copper
Element, Compound, or Mixture? Copper
Element, Compound, or Mixture? Jelly Beans
Element, Compound, or Mixture? Jelly Beans
Element, Compound, or Mixture? Table Sugar
Element, Compound, or Mixture? Table Sugar
Element, Compound, or Mixture? Diamond
Element, Compound, or Mixture? Diamond
Element, Compound, or Mixture? Tea
Element, Compound, or Mixture? Tea
Element, Compound, or Mixture? Salt
Element, Compound, or Mixture? Salt
Element, Compound, or Mixture? Neon Gas
Element, Compound, or Mixture? Neon Gas
Element, Compound, or Mixture? Salad
Element, Compound, or Mixture? Salad
Element, Compound, or Mixture? Pure Water
Element, Compound, or Mixture? Pure Water
Element, Compound, or Mixture? Aluminum
Element, Compound, or Mixture? Aluminum
Element, Compound, or Mixture? Lemonade
Element, Compound, or Mixture? Lemonade
Element, Compound, or Mixture? Silver
Element, Compound, or Mixture? Silver
Element, Compound, or Mixture? Sand
Element, Compound, or Mixture? Sand
Mixtures: Heterogeneous vs Homogeneous
HOMOGENOUS The prefix “homo” – indicate sameness Homogeneous – A homogeneous mixture has the same uniform appearance throughout. Many homogeneous mixtures are commonly referred to as solutions.
HETEROGENOUS The prefix “hetero” – indicate difference Heterogeneous - A heterogeneous mixture consists of visibly different substances or phases. The three phases or states of matter are gas, liquid, and solid.
Identification Chart Fixed composition?Can be broken down chemically? Uniform properties? If not, it’s an element If so it’s a compound If not, it’s a homogeneous mixture If not, it’s a heterogeneous mixture YES
Heterogeneous
Homogeneous
What is it? Trail Mix
Heterogeneous
What is it? Kool - Aid
Homogeneous
What is it? Tap Water
Homogeneous
What is it? White Vinegar
Homogeneous
What is it? Italian Salad Dressing
Heterogeneous
Try these……….. Raisin Bran
Orange Juice
Air
Chunky Soup
Hamburger
Cake Batter
Paint
Salad
Mineral Rock