Mid-Year Review

Chemisty, Earth History, Lithosphere, & Infectious dieases

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

Physical Properties & Changes

Physical Properties

Physical Properties are Anything you can observe about an object without altering its current state. The Properties include odor, density, mass, state, volume, and color.

Physical Changes

Physical Changes are changes made to an object that don't create a new substance. These changes include changes in color (painting a chair), shape (cutting an apple), or state (ice cream melting).

Chemical Properties & Changes

Chemical Properties

Chemical Properties are properties of a substance that can only be observed during a chemical reaction. They describe matter based on its ability to change into new matter with different properties. Chemical properties include flammability (how flammable something is) and reactivity (how reactive something is with another element).

Chemical Changes

Chemical Changes happen when one or more substances are changed into new substances that have new and different properties. Signs of a chemical change include: a new color appearing; heat, light, or sound being given off; bubbles of gas forming; a precipitate (solid) forming in a liquid; or when a change is impossible to reverse such as burning. A great example of a chemical change that you see is when you cook something or bake a cake (you can't reverse the cake to become eggs, icing, and cake mix can you?).

Atoms, Elements, Compounds, and Mixtures

Before we move on to the periodic table, I need to make sure you know a few words:

Atoms- The building blocks of all matter. Made of three parts: protons, neutrons, and electrons.

Elements- The most pure substances made of atoms that cannot be chemically broken down any further.

Compounds- Substance formed when two or more elements chemically combine

Mixtures- A combination of two or more substances that are mixed but not combined.


The Periodic Table of Elements

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The Periodic Table

The Periodic Table is an organized chart that shows every element. It is organized by periods and groups. Periods are the horizontal rows on the table. They organize elements by amount of shells around an atom in an element. Groups are the vertical columns and organize elements by the amount of electrons in the outer shell of an atom in an element.

Metals, Non-Metals, and Metalloids: Groups of the Periodic Table

Taking up most of the table, Metals are located from group 1 all the way to group 16. Metals are... metals. Metals include: Platinum, Gold, and Silver. Non-Metals are not metals. They are located from group 14 to 18. Mostly gas, Non-metals include Oxygen, Calcium, and Nitrogen. Though they may sound like a robot type from a "B" movie, Metalloids are like metals but aren't. This means they posses properties of metals and non-metals which means they are malleable and less conductive. The elements touching the staircase line on the table are considered metalloids. Aluminum, Arsenic, and Silicon.

Earth History