Warm Up: 9/24 (Back of NB) Use a periodic table and your knowledge of the element families to identify each element by name. 1. I am a member of the Carbon family with 14 electrons. 2. I am a member of the Alkaline Earth family and would have 6 energy levels. 3. I am a halide that is a liquid at room temperature. 4. I am a transition metal with 79 protons. 5. I am a member of the Alkali Metal family with 20 neutrons.

The answers are … 1. I am a member of the Carbon family with 14 electrons. 2. I am a member of the Alkaline Earth family and would have 6 energy levels. 3. I am a halide that is a liquid at room temperature. 4. I am a transition metal with 79 protons. 5. I am a member of the Alkali Metal family with 20 neutrons. Silicon Barium Bromine Gold Potassium

Both physical and chemical properties are used to describe substances.

Review: What are physical properties? List some examples of physical properties: Color Shape Odor Mass Volume Density Melting point Boiling point Solubility Malleability Ductility Conductivity

Chemical Properties Characteristics of substances that give them the ability to undergo a change that results in a new substance. Click here to watch a video

Examples of Chemical Properties: Flammability – easily set on fire. (ash and smoke are the new substances formed) Oxidation – reacting with oxygen (tarnish) Rust – some metals react with water to form a new substance, rust.

Examples of Chemical Properties: Radioactivity - An atom’s nucleus, if unstable, will spontaneously decompose to form a new atom with a higher stability. (loss of protons) The decomposition process is called radioactivity.

Properties Practice Use your notes to determine if these are examples of physical (p) or chemical (c) characteristics. _____ Sodium (Na) is a very reactive alkali metal. _____ Oxygen (O) is a gas. _____ Wood is flammable. _____ A ruby is red. _____ Copper (Cu) conducts electricity. _____ Water (H2O) freezes at 0 degrees Celsius. _____ Iron (Fe) reacts with water to form rust. _____ Silver (Ag) reacts with moisture in the air to form tarnish. _____ The chalkboard is magnetic. _____ Sand and dirt are mixed in a flower pot.

Properties Practice Physical property – Characteristics of substances that can be observed directly or measured with a tool without changing the identity of the substance. Chemical property – Characteristics of substances that give them the ability to undergo a change that results in a new substance.

Properties Practice: Answers __C___ Sodium (Na) is a very reactive alkali metal. __P___ Oxygen (O) is a gas. __C___ Wood is flammable. __P___ A ruby is red. __P___ Copper (Cu) conducts electricity. __P___ Water (H2O) freezes at 0 degrees Celsius. ___C__ Iron (Fe) reacts with water to form rust. __C___ Silver (Ag) reacts with moisture in the air to form tarnish. __P___ The chalkboard is magnetic. __P___ Sand and dirt are mixed in a flower pot.

Homework Add the following terms to you Unit 2 vocabulary list: Valence Electrons Chemical Property Oxidation Flammability Radioactivity Don’t forget to include: Detailed description Image or example Clue or connection Part IV of your project is due Friday! Your answers should reflect research, not what you can copy from your notebooks!