Activity Page # Warm Up p. 31: 1. What is the difference between a physical and a chemical property? 2. Which of the following are chemical changes? a) hair growing b) cloud formation c) making yogurt d) boiling water A student mixes three clear liquids together and observes the following: a powdery yellow solid is produced and the resulting mixture is very cold. Explain what has happened and how you know. Date Session # Activity Page # Bonding Notes 29 Bonding Worksheet 30 10/20-21 11 Unknown Substance w/Quick Write 31 Physical or Chemical?? 32 Homework: complete physical/chemical worksheet and unknown element properties test: Wednesday, 10/26 Review session Tuesday 10/25

QUESTION: If you have one or more unidentified substances, what could you do to start identifying them? ANSWER: Use their physical & chemical properties! Knowing the physical & chemical properties of different substances can be useful…

REMEMBER: Every single element on the Periodic Table, as well as other substances has its own set of physical and chemical properties like density, melting point, chemical reactivity etc.

Scenario 1: What Would You Do? You are thirsty and need water to survive. You have 3 containers of clear liquid…how can you start identifying what they are so you know which one is safe to drink? Which properties would be helpful?

Scenario 1: What Would You Do? You are thirsty and need water to survive. You have 3 containers of clear liquid…how can you start identifying what they are so you know which one is safe to drink? Which properties would be helpful? pH (water has a pH of 70, boiling point, density, reactivity (water does not react with most materials)

Scenario 2: What Would You Do? You have a cup full of sand and sugar. How would you separate them? What properties would be helpful?

Scenario 2: What Would You Do? You have a cup full of sand and sugar. How would you separate them? What properties would be helpful? Since you know that sugar is soluble in water and sand is not, you could add the 2 substances to a glass of water. You could pour the mixture over a filter so the sand is blocked, but the sugar water passes through. Then, allow the water to evaporate out and the sugar will be left over.

Scenario 3: What Would You Do? You work at a recycling plant and you must begin to separate the metals. What property would you use to help you?

Scenario 3: What Would You Do? You work at a recycling plant and you must begin to separate the metals. What property would you use to help you? They use large magnets. Since steel has magnetic properties, the steel cans will stick to the large magnet and be dropped off in one bin, while the aluminum cans are left behind to be dumped into another bin since they do not have magnetic properties.

Scenario 4: What Would You Do? There is a deposit of silver mixed with sulfur. Silver has a density of 10.5 g/cm3 and a melting point of 962 degrees Celsius. Sulfur has a density of 2.07 g/cm3 and a melting point of 115 degrees Celsius. How can these physical properties be used to separate silver and sulfur?

Scenario 4: What Would You Do? There is a deposit of silver mixed with sulfur. Silver has a density of 10.5 g/cm3 and a melting point of 962 degrees Celsius. Sulfur has a density of 2.07 g/cm3 and a melting point of 115 degrees Celsius. How can these physical properties be used to separate silver and sulfur? Heat the mixture until the sulfur melts. The solid silver will sink to the bottom because it is denser and can be removed leaving the liquid sulfur behind.