Mid-Year Reveiw

Chemistry,Earth History, Infectious Diseases and Lithosphere

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

Physical Properties

Odor, Taste, Density, Volume and Color are all physical properties and can be observed or measured without being changed.

Chemical Properties

Flammability and Reactivity are chemical properties but can only be observed during a chemical reaction. They describe matter based on its ability to change into a new matter with different properties.

Physical and Chemical Change

Peanut butter being spread on a piece of bread or ice cream melting in the hot sun are examples of chemical change because they do not create a new substance. But striking a match to create a flame is a chemical change because you cannot make the match not have burn marks and a gas was created.

Elements Mixtures and Compounds

Elements only have one type of atom. They cannot be broken down any further. Compounds are made of two or more different atoms that are chemically bonded and can only be separated chemically. Mixtures are a combination of two or more pure substances that are held together by physical forces, not chemical.

Periodic Table

The periodic table is a list of all the known elements. It is organized by increasing atomic number. There are two main groups in the periodic table: metals and nonmetals.The left side of the table contains elements with the greatest metallic properties. As you move left to right the elements become less metallic with the far right side of the table consisting of nonmetals. The elements in the middle of the table are called "transition" elements because they have both metallic and nonmetallic properties.The table is also arranged in vertical columns called "groups" or "families" and horizontal rows called "periods". Each arrangement is significant. The elements in each vertical column or group have similar properties. Group one elements all have the electron in their outer shells . This gives them similar properties.Group two elements all have two electrons in their outer shells. This also gives them similar properties. Not all 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.

Law of conservation of mass

Matter cannot be created or destroyed it can only be transferred state to state.


Atomic mass- The mass of an atom of a chemical element

Atomic number- Number of protons in the nucleus

Earth History

Law of superposition

States that in rock layers the rocks on top are younger than the ones on bottom. Only applys to undisturbed rock layers.

Index fossils

Index fossils are fossils that scientists use to determine the age of other fossils.

Ice Cores

Ice Cores are cylinders of ice about a meter long that were drilled out of glaciers or ice caves that were formed millions of years ago and they trap samples of the earths atmosphere in frozen air bubbles that scientists extract to determine what the climate was like when the sample was captured. They determine the age of the ice sample by observing the coloration in the ice layers

Geologic Time Scale

A timescale used by geologists that consists of all recorded earth history.

Relative and Absolute Dating

Relative dating is a method used by scientists only in undisturbed rock layers that determines the relative age of a fossil or a rock layer. Absolute dating however is a method used by scientists that determines the exact age of a fossil or rock layer.

Half-life/Radioactive decay

A half life is a term used when trying to determine the age of something by using the method of Radioactive Decay. It is a determination of time that tells you how much carbon 14 has turned into carbon.


Fossil- Naturally preserved remains

Uniformitarianism- Means that things that happen in the world 1 million years ago still happen today. Like rain.

Fossil Record- Record of all known fossils

Infectious Disease


Different types of microorganisms include:

viruses, bacteria, protozoa, parasites, fungi and algae

These microorganisms are microscopic, unicellular and very diverse and may of them cause disease.

Viruses, Bacteria, Fungi and Parasites

Viruses are considered to be non-living but they affect living things. In order for viruses to attack and reproduce, they need a host cell. Viruses reproduce by invading and killing other healthy cells. Viruses are transmitted in various ways including human contact, Insect vectors and drinking water. To control virus outbreaks we use vaccines.

Characteristics of bacteria include: being prokaryotic, unicellular, they can live with or without oxygen and in extreme conditions. Bacteria reproduce by Binary fission and is transmitted by Direct or indirect, sneezing, coughing and contaminated surfaces. Sicknesses caused by bacteria are treated with antibiotics.

Fungi are eukaryotic