Mid-Year Review

Chemistry, Earth history, Infectious Diseases

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

Physical and chemical properties

  • Physical properties- They can be observed or measured without changing the matter's identity.
  • Chemical properties- They describe matter based on it's ability to change into new matter that has different properties.
Physical and Chemical change
  • Physical- A physical change does not form a new substance.
  • Chemical- In a chemical change one or more substances are changed into new substances that have new and different properties
Elements, Compounds and Mixtures
  • Elements- Building blocks of matter made out of atoms.
  • compounds- A substance formed when 2 or more elements are chemically combined
  • Mixtures- A combination of 2 or more different substances that is mixed but not combined
Periodic Table
  • Groups- Columns of elements on the periodic table that share common properties
  • Periods- The seven horizontal rows on the Periodic Table
  • Metals, Non- Metals and Metalloids- alkali metals are found on the left side of the table starting with lithium and ending with Francium. Non-metals are scatter around a bit hydrogen, carbon, nitrogen, oxygen, phosphorous, and sulfur. Metaloids start with boron and goes in a diagonal line down to polonium.
  • Atomic number, mass, protons, neutrons and electrons- The atomic number is the number at the top of the element. the atomic mass is the number at the bottom of the element. The protons, neutrons, and electrons are the three parts of a atom.
The law of conservation of mass- Matter can not be created nor destroyed.


  • Compound- a substance formed when two or more elements chemically combine.
  • Matter- anything that has mass and takes up space.
  • solution- a substance made as a result of mixing a solid and a liquid and the solid dissolved.
  • Atom- the basic building block of all matter.
  • Mixture- a combination of 2 or more different substances that is mixed but not combined.
  • Element- Building blocks of matter made of atoms.

Earth History

The law of superposition- The oldest layers are located at the bottom and the youngest layers are located at the top.

Index Fossil- A fossil that is found in the rock layers of only one geologic age and is used to establish the age of the rock layers.

Ice Cores- A core of ice removed from a deep layer of ice/snow to find the history of it.

Geologic time scale- a system of chronological measurement that relates stratigraphy to time.

Relative dating- science of determining the relative order of past events (estimated age)

Absolute dating- is the process of determining an approximate computed age in archaeology and geology.

Half-life- is the amount of time required for a quantity to fall to half its value as measured at the beginning of the time period.

Radioactive decay- is the process by which a nucleus of an unstable atom loses energy by emitting ionizing.


  • absolute dating- the age of a rock given as the number of years since rock formed
  • Ice cores- sample that is typically removed from an ice sheet.
  • law of superposition- The oldest layers are located at the bottom and the youngest layers are located at the top.
  • geology- the study of the history of the earth.
  • Relative dating- the age of a rock compared to the ages of rock layers
  • index fossil- fossils of widely distributed organisms that lived during only one short period.

Infectious Diseases


  • virus- an infective agent that typically consists of a nucleic acid molecule in a protein coat, is too small to be seen by light microscopy, and is able to multiply only within the living cells of a host.
  • Bacteria- Bacteria constitute a large domain of prokaryotic microorganisms. Typically a few micrometers in length, bacteria have a number of shapes, ranging from spheres to rods and spirals.
  • Fungi- A fungus is any member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms.

  • Parasite- an organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's expense.
Epidemic- a widespread occurrence of an infectious disease in a community at a particular time.

Pandemic- A disease spread over a large place, world, continent, etc.

Prevention/Treatment- vaccines help prevent viruses, antibiotics help treat bacteria infections


  • Careers- There's different careers in biotech, agriculture, labs and more.
  • agriculture- biotech helps the farmers make products that help them but not us.
  • medicine- Creates more vaccines and more medicine for people.