Chemical Properties February 17 + 18

Quiz Please take out a sheet of paper and number is 1-6

1. Which one of the following is a compound? A. O2 B. Air C. H2O D. Au

2. Which of the following is a chemical property of matter? A. Oxidation B. Melting Point C. Density D. Solubility

3. In which of the following phase changes do we add heat? A. Condensation B. Vaporization C. Freezing D. Deposition

4. Which of the following is a heterogeneous mixture? A. Saturated Salt Water B. Gold C. Pizza D. H2O

5. What is the density of a 24 g brick of gold with a volume of 8 mL? A. 0.3 g/mL B. 300 g/mL C. 192 g/mL D. 3 g/mL

6. At what point do we see a liquid and gas? Point B B. Point C C. Point D D. Point E

Chemical Properties The characteristics of a substance that can be observed when we change the identity of the substance. Remember this does not involve just changing what it looks like, but changing what it is! When a substance changes into one or more new substances this is a chemical change.

Question Is water melting a physical or chemical change? Why?

Signs of a Chemical Change Color Change Production of gases or light An increase/decrease in temperature The formation of a solid substance (precipitate) out of two or more liquids.

Chemical Reaction When a chemical change occurs, a chemical reaction has happened! Reactants- The original substances that change Products- The substances that are formed

Reactivity An element’s tendency to combine with other elements to form compounds.

Oxidation (corrosion) In chemistry, this term has several meanings. The most specific definition refers to the loss of one or more electrons by an atom, ion, or molecule. We will use this term to mean, a reaction between a metal and atmospheric oxygen (O2) to produce a compound called a metal oxide. We also call this corrosion. The most common one you are familiar with is rust!