Mid-Year Review

Chemistry, Earth History, Infectious diseases & 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- A characteristic that you can observe without changing the composition of the substance. Ex: state of matter, color, shape, texture, etc.


Chemical properties- A characteristic that you can only observe by changing the identity of the substance. Ex: Flammability, reactivate, toxicity


Physical Change- Any change that does not involve a change in the substance's chemical identity.

Chemical Change- Any change in matter that results in the formation of new chemical substance.

Element- Building blocks of matter made of atoms

Compounds- Substance found when two or more elements chemically combine. Ex: H2O, NaCI

Mixtures- Combination of 2 or more different substances that is mixed but not combined. There are Heterogeneous which means that you can see and separate the parts easily (ex: bowl of cereal). There are Homogeneous which means you cannot see the individual parts and cannot be separated (ex: water, perfume)

Periodic Table- There are groups and periods. Groups are columns (up & down) of elements on the periodic table that share common properties. Periods are the seven horizontal (left to right) rows on the periodic table.

Metals- They are solid, shiny, ductile and malleable. They are also conductors.

Metalloids- They have properties that are cross between metals and metalloids.

Non- metals- They have opposite properties of metals.

The atomic number is the number of protons in the nucleus. The atomic number is located above the symbol.

The symbol is a one or two letter abbreviation.

The atomic mass is the number of neutrons and the number of protons is the nucleus. The atomic mass is located at the bottom of the element below the symbol.

The Law of Conservation of Mass states that matter cannot be created nor destroyed. It can only be transferred from state to state.

Vocabulary- Matter is anything that has mass and takes up space. Atoms are the basic building block for all matter. Solution is a substance made as a result of mixing a solid and liquid and dissolves.

Earth History

Law of Superposition- Younger rocks lie above older rocks if the layers have not bee disturbed.

Index Fossils- Fossils that can be compared to help identify specific periods of geologic time.

Ice Cores-

Geologic Time Scale- Used by geologists to describe the timing and relationships between events that have occurred throughout Earths history.

Relative Dating- It gives a comparison too guess a date.

Absolute Dating- The exact date when something formed.

Half Life- The time taken for radioactivity of specified isotope.

Vocabulary- Unitarianism is the idea that laws and processes that happen of Earth have always happened and continue to happen everywhere in the universe. Fossil Record is a record of the total number of fossils that have been discovered. Isotopes are different versions of the same element. Geology is the study of the origin/ history and structure of the Earth. Fossils are naturally preserved remains or traces of animals or plants that lived in the geologic past.

Infectious Diseases

Microorganisms-

Virus- Non- Living