Homework!

Objective 1: Measuring Matter
1. Why is mass more useful than weight for measuring matter? Mass takes up space and is made of matter, therefore it would be more useful to weigh matter in mass than a regular weight like lbs, etc.
2. A plastic box is 15.3 cm long, 9.0 cm wide and 4.5 cm high. What is the volume? Include units. 619.65cm^3 (cubed)
3. What is the unit of measurement for density? grams
4. Please write the formula for finding density. d = g/v
5. What is the formula for finding volume? L x W x H

Objective 2: Changes in Matter1. What is the main difference between a physical change and a chemical change? Chemical is the bonds between adams (cough) atoms; Physical change is the motion of the atoms (transforms into kinetic)
2. What are the four ways that chemical changes can occur? Ionic bonds, metallic bonds, covalent bonds, anionic bonds (?)
3. What is the Law of Conservation of Mass? Who created the law? Antoine Lavoisier and it states that matter can not be created nor destroyed.4. How are temperature and thermal energy different? Temperature is the measure of the average motion of the particles in a substance. Thermal energy is the particles moving around.
5. Please give an example of an exothermic reaction and an endothermic reaction. Exothermic produces heat. Ex- Elephant toothpaste. When hydrogen peroxide combines, it goes boom and heats up. Endothermic: It gets cold. Ex- Freezing water (?)

Objective 3: Energy and Matter

1. What are some of the forms of energy related to changes in matter? Potential, Kinetic, Chemical, Thermal, Electric, Electromagnetic
2. A rolling bowling ball has __kinetic__ energy.
3. A bowling ball sitting still has __potential__ energy.
4. What is electromagnetic energy? A type of energy that has to do with giving out or taking in energy from objects in the form of electrical waves, or radiation.
5. What is the energy of electrons moving from one place to another? Please give an example. Electric energy. Ex- the atoms travelling from an electrical chord to power laptops, etc.

Objective 4: State Changes

1. How does the thermal energy of particles at a warmer temperature compare to the thermal energy of particles at a cooler temperature? When it's at a warmer temperature, the atoms are moving around and excited-like. When it's cooler, they're more calm and still.
2. Why does ice cream melt on a warm summer day? Because the temperature is warm, making the particles in the ice cream to jump around (thermal energy). The pressure of it causes it to melt.
3. What does the melting point of particles have to do with vibrating particles? When the pressure of the vibrating particles reaches melting point, it melts.
4. When does condensation occur? When particles begin to melt. (ex. When you take a cold water bottle outside in the hot weather, it beings to condensate.)
5. Sublimation results under which conditions? Sublimation is when a solid goes to a gas (or gas to solid), skipping the liquid stage. An example would be dry ice, as it freezes, yet when it reacts with water, it steams up and goes to a gas (?)

Objective 5: Boyle's Law (Click Here for More Info)

1. What relationship is described by Boyle's Law? Pressure and volume.2. Why do scientists only HALF fill high-altitude balloons? "While one doubles, the other halves." If the volume and pressure are full, temperature must be half.
3. What is the formula for Boyle's Law? pV = k
4. How does Boyle's Law apply to physicians? Taking a guess here by saying when they take your blood pressure?
5. SCUBA divers rely on Boyle's Law for what purposes? Taking another guess here by saying when they go down into the ocean, the pressure of the water and everything has to stay regulated by using this law?

Objective 6: Charles' Law (Click Here for More Info)1. What is Charles' Law? It shows how gases expand as they get warmer.
2. As the temperature of a gas increases, the gas molecules move more __room to expand__.
3. Who was the first person to fly in a hydrogen balloon? Jean-Francois Pilatre de Rosier and Francois Laurent d'Arlandes.
4. What happened to Charles' balloon after his first flight in 1783? Hahaha, local peasants destroyed it with pitchforks. But the part you're probably looking for is when the hot gas cooled, the balloon contracted.
5. What factor is kept unchanged when demonstrating Charles' Law? k (constant) pressure stays same.