2. Physical and Chemical Properties By: Mr. Castillo & Ms. Garcia

3. Table of Elements We learned elements are a pure substance made of only one type of atom. That the table of elements is a list of elements organized by their atoms properties. Also, that elements have Groups and Periods. Now, lets learn about Chemical and Physical properties that determine how one element interacts with another. Property: characteristic that helps to define or classify a substance.

4. Physical Properties: any property observed without changing the substance. Certain properties increase and decrease along periods (rows); Atomic Number (protons) and Atomic Mass (Protons & Neutrons). Examples: color, mass, density, texture, dissolving, hardness, melting point, or state of matter (solid, liquid, gas, and plasma). Properties

5. Physical Properties

6. Chemical Properties: a property that allows a substance to react, changing it into a new substance; determined by valence electrons. *Similar chemical properties occur down a group. Reactivity: ability of an atom/molecule to undergo a chemical reaction with other atom/molecules ;determined by valence electrons. Examples: rust, burning, gas bubbles (CO 2 ), sunburn, and decomposing matter (food rotting). Properties

7. Chemical Properties

8. Isotopes and Ions Isotopes: Atoms of an element with different number of neutrons; Atomic Mass is different. Ions: Atoms of an element with a different number of electrons; a charged atom (+,-). - - - - - - - - -

9. Why do we need to know about properties? Properties allow us to identify an element. They help us understand how elements behave and react under various conditions. Properties

10. Any Questions