Mid-Year Review

Chemistry, Earth history, Infectionus Disease

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

A physical properties is a characteristic that can be observed or measured without changing it. examples of physical properties are odor, density, mass, volume, state, color.

A chemical properties can only be observed during a chemical reaction. It describes matter based on its ability to change into new matter with different properties. examples are flammability and reactivity.

A physical change does not form a new substance. examples are ice cream, sandwich, cutting food in half.

A chemical change is one or more substances that are changed into new substances that have new and different properties. examples a new color appears, heat light or sound is given off, bubbles of gas are formed.

Elements are arranged on the periodic table.

mixtures are two or more elements chemically combined.

Compounds are two or more atoms or different elements combined to make a substance.

Periodic Table is a table that shows all the elements arranged in order by the atomic number. They are usually in rows.

Groups Group 1 is alkali metals and group two is alkaline earth metals.

group three through twelve are transitional metals

Lanthanides and Actinides are placed on the bottom of the periodic table.

metals are placed in group 1 and 2. non-metals are now in row 14 15 16 17. Metalloid metals are placed elements 5 14 32 33 51 85.

Atomic number is the number of an elements atomic mass is the same number of protons and neutrons in the atom. protons and the neutrons will always stay the same.

Earth history

The law of superposition is a key axiom based off observations of natural history.

Index fossil is a fossil that is useful for dating and correlating the strata in which it is found.

Ice core is a sample of ice that can tell you the past climate by holding carbon dioxide.

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

Relative dating is the dating of a rock compared to the age of rock layers.

Absolute dating is the age of a rock given as the number of years since the rock formed.

Half-Time is the time taken for the radioactivity of a specified isotope to fall to half its original value.

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

Vocabulary Geology, Relative Dating, Absolute Dating, Index fossil, Law of superposition, Ice core.