Mid-Year Review
Chemistry, Earth History, Infectious Disease, Lithosphere
Chemistry- 8.P.1- Understand the properties of matter and changes that occur when matter interacts in an open and closed container.
Chemical Properties- A characteristic that you can only observe by changing the identity of the substance. Ex; Flammability, reactivity, oxidation, and toxicity.
Physical Change- Any change that does not involve a change in the substance's chemical change. Ex; Wood chipper, liquid to gas, Ice to water. (Physical changes can be undone.
Chemical Change- Any change in matter that results in the formation of a new chemical substance. Ex; Eggs, Cake, tree burning. (Can't be reversed)
Elements- Simplest form of matter. Composed of a single kind of atom.
Compound- Made up of 2 or more atoms that are chemically combined.
Mixtures- A combination of 2 or more substances that are not chemically combined.
- Homogeneous- You can't see the individual parts of the mixtures.
- Heterogeneous- You CAN see the individual parts of the mixtures.
Groups- Columns up and down of elements on the Periodic Table that share common properties.
Periods- The horizontal rows of the periodic table.
Metals- They are solid. They are shiny, good conductors of electricity and heat. They can be made into thin wires.
Non-metals- Brittle, not good conductors of both heat and electricity, and can gain electrons in chemical reactions. Some nonmetals are liquid.
Metalloids- have properties that are somewhat of a cross between metals and nonmetals, because of their unique conductivity properties (they only partially conduct electricity) they can be used as a semiconductor or in computer chip.
Atomic Number- The number of protons in the atom's nucleus.
Atomic Mass- The mass of the atom.
Protons- a particle of a positive electric charge in an atom.
Electrons- a particle of a negative electric charge in an atom.
Neutron- Same mass as a proton but without the electric charge.
Law of Conservation of Mass- States that matter cannot be created or destroyed; it can only be transferred from state to state.
Vocab- Compound, Matter, Solution, Atom, Mixture, Element
Earth History
Index Fossils- Found in rock layers, rock layers of only 1 geological age.
Ice Cores- A cylinder of ice that tells us about Earths history. Contains carbon dioxide.
Geologic Time Scale- describe the timing and relationships between events that have occurred throughout Earth's history.
Relative Dating- Used to determine the age of a fossil by looking at its positions in the layers of sedimentary rocks.
Absolute Dating- Used to determine the exact age of a fossil.
Half-Life/Radioactive Decay-a nucleus of an unstable atom loses energy as it gets older.
Vocab- Absolute Dating, Relative Dating, Half-Life, Absolute, Law of Superposition, Geology, Index Fossil, Fossil, Uniformitarianism, Geologic Time Scale
Infectious Disease
Virus- small infectious microbe that replicates only inside the living cells of other organisms called host cell.
Bacteria- Single-celled organisms that lack a nucleus.
Fungi- live on dead or decaying things.
Parasite- an organism that lives in or on another organism.