Mid-Year Review

Chemistry, Earth History, Infectious Diseases

Chemistry- 8.p.1 - Understanding 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.

Chemical Properties- A characteristic that you can only by changing the identity of the substance.

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.

Element- Made up of one type of atom, cannot be separated into simpler substance by physical or chemical means and is located on the periodic table.

Compounds- Are made of 2 or more atoms of different elements that are bonded together, and is made up of elements in a specific ratio that is always the same.

Mixtures- Anything that takes up space (volume) and has mass.

Periodic table- The Periodic Table is a list of all the known elements.

Groups- Columns (up and down) of elements on the periodic table that share common properties.

Periods- The periodic table has seven horizontal (left to right) rows known as periods.

Metals- Metals are on the left side of the periodic table.

Non-Metals- Non Metals are on the right side of the periodic table.

Metalloids- Metalloids are in the middle of the staircase.

Atomic Number- Number of protons and electrons in an atom of one element.

Atomic Mass- The sum of protons and neutrons in the nucleus of an atom.

Protons- A stable subatomic particle occurring in all atomic nuclei, with a positive electric charge.

Electrons- A stable subatomic particle with a charge of negative electricity.

Law of Conversation of Mass- States that matter cannot be created nor destroyed; it can only be transferred from state to state.

Vocabulary- The body of words used in a particular language.

Earth History:

Law of superposition- Younger rocks lie above older rocks if the layers have not been distributed.

Index fossils- The trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock.

Ice Cores- Blocks of ice that indicate the weather of the snowfall.

Geologic time scale- it describes the timing and relationships between events that have occurred throughout Earth's history.

Relative Dating- The age of a rock compared to the ages of rock layers.

Absolute Dating- The age of a rock given as the number of years since the rock formed.

Half-Life- The time taken for the radioactivity of a specified isotope to fall to half it's original value.

Radioactive Decay- Is the breakdown of an atomic nucleus resulting in the release of energy and matter from the nucleus.

Infectious Disease:

Microorganism- A microscopic organism, especially a bacterium, virus,or fungus.

virus- An infective agent that typically consists of a nucleic acid molecule in a protein coat.

Bacteria- A member of a large group of unicellular microorganisms that have cell walls.