Mid-Year Review

Chemistry,Earth History,Infectious Disease

Chemistry- 8.P.1- Understand the properties of matter and changes that occur when matter interacts in an open and closed container.

1.Physical and Chemical Properties-

  • Physical properties are characteristics that you can observe without changing the composition of the substance. Describes how something looks, smells, feels, taste, or sounds.you use your five scenes too observe physical properties. EX:Color,Shape,Texture,Smell,Size-dependable property,State of matter

  • Chemical properties are characteristics that you can only observe the changing the identity of the substance. EX: flammability, reactivity.

2. Physical and Chemical Change-

  • Physical changes are any change that does not involve a change in the substances chemical identity typical physical changes can be reversed does not form a new substance EX: Water
  • Chemical changes are any change in matter that results in the formation of new chemical substance or when one or more substances are changed into new substances that have new and different properties.Chemical change typically can not be reversed. A new substance is formed as a result or a chemical reaction. EX:Egg, a new color, Heat light or sound is given off of or observed, bubbles of gas are formed a new odor may be noticed, a solid material forms in a liquid, the change is difficult or impossible to reverse.
3. Element, Compound, Mixture

  • Elements are made of one type of atom can not be seperated into simpler substances by physical or chemical means. located on the periodic table. A combination or two or more substances that are mixed but not combined . EX: Bowl or cereal, trail mix, and sand at the beach.
  • Compounds are made of two or more atoms of different elements that are bounded together. Made of elements in a specific ratio that is always the same has a chemical formula can only be seperated chemically and physically EX: Table salt, sugar and water (H2O)
  • Mixtures are combinations of 2 or more pure substances that are held together by physical force not chemical. EX: Rocks, jellybeans,tea, salad, lemonade,sand
4. Periodic Table,Metals and Metalloids,and non metals

  • The periodic table is sounded out by increasing atomic number. There are two main groups on the periodic table: metals and nonmetals. The left side of the table contains elements with the greatest metallic properties.As you move form the left to the right the elements become less metallic with the far right side of the table consisting nonmetals. The elements in the middle of the table are called "transition" elements because they are changed from metallic properties to non metallic properties.A small group whose members touch the zigzag line are called metalloids because they have both metallic and non metallic properties.
5. Groups and periods

The horizontal rows are called periods each arrangement is significant. The elements in each vertical column or group have similar properties. Groups 1 elements all have 2 electrons int their outer shell. This gives them similar properties. Groups 2 elements all have 2 electrons in their outer shells. This also gives them similar properties. Not all of the groups, however, hold true for this pattern. The elements in the first period or row all have one shell. The elements in period 2 all have 2 shells. The elements in period 3 have 3 shells and so on.

. Protons neutrons are all inside the nucleus electrons outside the nucleus to identify an atom you count the number of electrons and match it to the atomic number on the periodic table.