Objective 5:
1. The relationship described in Boyle's Law is between the volume and the pressure of a gas.
2. Scientists only HALF fill high-altitude balloons because as the altitude increases, the pressure decreases. This causes the balloon to get bigger (because volume and pressure are related *when pressure decreases, volume increases*), so if you fill it up all the way, when it expands it will pop.
3. The formula for Boyle's Law is: PV=k. P is pressure of the system, V is volume of the gas, and k is a constant value (of the pressure and volume.)
4. Boyle's Law is useful for physicians because, when they put patients on oxygen (like on the tanks), then they can see how much is in tank so they know when to refill it. They find this out by multiplying the pressure of the oxygen tank by the volume of the tank and find out how much there is / needs to be.
5. Scuba divers use Boyle's Law in the same way that doctors do. When they go underwater, they carry oxygen tanks. They use Boyle's Law to see how much oxygen they have / need.
Citations:
http://en.wikipedia.org/wiki/Boyle's_law
http://wiki.answers.com/Q/Why_do_most_helium_filled_balloons_burst_as_they_ascend_to_high_altitudes
http://wiki.answers.com/Q/What_is_the_formula_of_Boyle's_law
Monday, November 8, 2010
Sunday, November 7, 2010
Test 8 ~ Objective 4
Objective 4:
1. The thermal energy (heat) of objects at a warmer temperature is a lot warmer than the thermal energy of objects at a cooler temperature. This is because particles in these objects react to heat by jumping around, or getting excited, which causes an object to be warm. If there is no heat, the particles aren't jumping around, so there is no heat produced.
2. Ice cream can melt from temperature. This is because, since it is so hot outside, the ice cream is absorbing a lot of energy from the sun, which causes it to melt because of the question above (#1.) Another reason why ice cream melts is the ingredients inside of it, which includes fat. Non-fat ice cream will melt more slowly than regular ice cream because, since there is less fat, there is less water. In non-fat ice cream, there is more water, which means it will have to absorb more energy in order to melt.
3. The melting point of particles has to do with the vibrating particles because when particles in an object absorb heat, or energy, they start to move around (vibrate), and this causes them to melt. The more particles vibrate, the faster they melt.
4. Condensation occurs when humid air, or air that is "saturated with moisture" cools down very quickly. This causes the water to make little droplets. An example of this is when there is condensation on a cup with cold liquid inside of it.
5. Sublimation is when a solid goes straight to a gas, without being a liquid first. Sublimation happens when there is low humidity and the temperature is just below freezing.
Cites:
http://www.post-gazette.com/pg/09187/981622-115.stm
http://wiki.answers.com/Q/Why_does_condensation_occur
http://www.newton.dep.anl.gov/askasci/chem00/chem00402.htm
1. The thermal energy (heat) of objects at a warmer temperature is a lot warmer than the thermal energy of objects at a cooler temperature. This is because particles in these objects react to heat by jumping around, or getting excited, which causes an object to be warm. If there is no heat, the particles aren't jumping around, so there is no heat produced.
2. Ice cream can melt from temperature. This is because, since it is so hot outside, the ice cream is absorbing a lot of energy from the sun, which causes it to melt because of the question above (#1.) Another reason why ice cream melts is the ingredients inside of it, which includes fat. Non-fat ice cream will melt more slowly than regular ice cream because, since there is less fat, there is less water. In non-fat ice cream, there is more water, which means it will have to absorb more energy in order to melt.
3. The melting point of particles has to do with the vibrating particles because when particles in an object absorb heat, or energy, they start to move around (vibrate), and this causes them to melt. The more particles vibrate, the faster they melt.
4. Condensation occurs when humid air, or air that is "saturated with moisture" cools down very quickly. This causes the water to make little droplets. An example of this is when there is condensation on a cup with cold liquid inside of it.
5. Sublimation is when a solid goes straight to a gas, without being a liquid first. Sublimation happens when there is low humidity and the temperature is just below freezing.
Cites:
http://www.post-gazette.com/pg/09187/981622-115.stm
http://wiki.answers.com/Q/Why_does_condensation_occur
http://www.newton.dep.anl.gov/askasci/chem00/chem00402.htm
Thursday, November 4, 2010
Test 8 ~ Objective 3
Objective 3:
1. Some of the forms of energy related to changes in matter are chemical energy (because it makes a chemical reaction, which can make a different substance, such as plasma), and thermal energy.
2. A rolling ball has kinetic energy (because it is in motion.)
3. A bowling ball sitting still has potential energy (because it is sitting in place.)
4. Electromagnetic energy is energy of or from radiation. It can transmit energy in the form of waves from one place to another. The stuff that it transmits can be in the form of heat, light, or anything else.
5. The energy of electrons moving from one place to another is called electric energy. An example is this is charging a computer. The electrons go from a power line, into a wire that connects our school, through the wall and into the power cord, and then finally (when you plug it in) the electrons go into your computer.
Cites:
http://www.buzzle.com/articles/what-is-electromagnetic-energy.html
http://www.historyoftheuniverse.com/chemener.html
1. Some of the forms of energy related to changes in matter are chemical energy (because it makes a chemical reaction, which can make a different substance, such as plasma), and thermal energy.
2. A rolling ball has kinetic energy (because it is in motion.)
3. A bowling ball sitting still has potential energy (because it is sitting in place.)
4. Electromagnetic energy is energy of or from radiation. It can transmit energy in the form of waves from one place to another. The stuff that it transmits can be in the form of heat, light, or anything else.
5. The energy of electrons moving from one place to another is called electric energy. An example is this is charging a computer. The electrons go from a power line, into a wire that connects our school, through the wall and into the power cord, and then finally (when you plug it in) the electrons go into your computer.
Cites:
http://www.buzzle.com/articles/what-is-electromagnetic-energy.html
http://www.historyoftheuniverse.com/chemener.html
Wednesday, November 3, 2010
Test 8 ~ Objective 2
Objective 2:
1. The main difference between a chemical change and a physical change is that in a physical change, no new substances are formed, and in a chemical change, a new substance is formed. An example of a physical change is freezing water (you can melt it and it still is water.) An example of a chemical change is burning something because the solid that you burn breaks down (because of the heat- SUBLIMATION!!) into many other elements, such as carbon dioxide.
2. The four ways that chemical changes can occur are a solid is formed, a color change happens, a gas is produced (you can tell by bubbles forming), and light, heat, or sound is produced.
3. The Law of Conservation of Mass basically says that mass of an isolated system (which cannot exchange heat, work, or matter with its surroundings) cannot be created or destroyed, but it can be moved around. The law was created by Empedocles, who an ancient Greek philosopher. His idea was "Nothing comes from nothing."
4. Temperature and thermal energy are different because temperature isn't actually energy, but it is a number that is related to energy, or heat ( is related to the average kinetic energy of the molecules in a substance). Thermal energy is ACTUAL energy that is measured in energy units and is the measure of energy in a substance.
5. An exothermic reaction is a reaction that releases energy in the form of heat. An example of this is elephant toothpaste, which reacted by getting very hot. An endothermic (absorbs heat from surroundings) reaction is when an object gets cold (because it is taking in the heat, not releasing it.) An example of this is the experiment that Gabby and I did because the acentric acid and the baking soda reacted to each other by getting very cold.
Cites:
http://www.physlink.com/education/askexperts/ae244.cfm
http://en.wikipedia.org/wiki/Conservation_of_mass
http://zonalandeducation.com/mstm/physics/mechanics/energy/heatAndTemperature/heatAndTemperature.html
http://en.wikipedia.org/wiki/Endothermic_reaction
http://wiki.answers.com/Q/Four_ways_you_can_tell_a_chemical_change_has_taken_place
1. The main difference between a chemical change and a physical change is that in a physical change, no new substances are formed, and in a chemical change, a new substance is formed. An example of a physical change is freezing water (you can melt it and it still is water.) An example of a chemical change is burning something because the solid that you burn breaks down (because of the heat- SUBLIMATION!!) into many other elements, such as carbon dioxide.
2. The four ways that chemical changes can occur are a solid is formed, a color change happens, a gas is produced (you can tell by bubbles forming), and light, heat, or sound is produced.
3. The Law of Conservation of Mass basically says that mass of an isolated system (which cannot exchange heat, work, or matter with its surroundings) cannot be created or destroyed, but it can be moved around. The law was created by Empedocles, who an ancient Greek philosopher. His idea was "Nothing comes from nothing."
4. Temperature and thermal energy are different because temperature isn't actually energy, but it is a number that is related to energy, or heat ( is related to the average kinetic energy of the molecules in a substance). Thermal energy is ACTUAL energy that is measured in energy units and is the measure of energy in a substance.
5. An exothermic reaction is a reaction that releases energy in the form of heat. An example of this is elephant toothpaste, which reacted by getting very hot. An endothermic (absorbs heat from surroundings) reaction is when an object gets cold (because it is taking in the heat, not releasing it.) An example of this is the experiment that Gabby and I did because the acentric acid and the baking soda reacted to each other by getting very cold.
Cites:
http://www.physlink.com/education/askexperts/ae244.cfm
http://en.wikipedia.org/wiki/Conservation_of_mass
http://zonalandeducation.com/mstm/physics/mechanics/energy/heatAndTemperature/heatAndTemperature.html
http://en.wikipedia.org/wiki/Endothermic_reaction
http://wiki.answers.com/Q/Four_ways_you_can_tell_a_chemical_change_has_taken_place
Tuesday, November 2, 2010
Test 8 ~ Objective 1
Objective 1:
1. Mass is more useful than weight in measuring matter because mass is always the same, and weight changes depending on gravity. Since scientist don't want to get different answers, they use mass because it never changes, or it is a constant. I think (I am not sure) that an example of this is when you are on the moon, you have a lighter weight (because there is less gravity) than when you are on earth, but you have the same mass in both places.
2. The volume of the plastic box is 619.65 cm3 (centimeters cubed.)
3. The unit of measurement for density is the size (ex: g) and the unit of volume (cm3 *centimeters cubed*.) For example, is something that was 2 grams had a volume of 12 cm3 (centimeters cubed), you would put 2 g/ 12 cm3 (centimeters cubed.)
4. The formula for finding density is mass divided by volume, or mass over volume.
5. The formula for finding volume is length multiplied by width multiplied by height (l*w*h)
Cites:
http://wiki.answers.com/Q/Why_is_mass_more_useful_than_weight_for_measuring_matter
http://en.wikipedia.org/wiki/Density
http://en.wikipedia.org/wiki/Volume
1. Mass is more useful than weight in measuring matter because mass is always the same, and weight changes depending on gravity. Since scientist don't want to get different answers, they use mass because it never changes, or it is a constant. I think (I am not sure) that an example of this is when you are on the moon, you have a lighter weight (because there is less gravity) than when you are on earth, but you have the same mass in both places.
2. The volume of the plastic box is 619.65 cm3 (centimeters cubed.)
3. The unit of measurement for density is the size (ex: g) and the unit of volume (cm3 *centimeters cubed*.) For example, is something that was 2 grams had a volume of 12 cm3 (centimeters cubed), you would put 2 g/ 12 cm3 (centimeters cubed.)
4. The formula for finding density is mass divided by volume, or mass over volume.
5. The formula for finding volume is length multiplied by width multiplied by height (l*w*h)
Cites:
http://wiki.answers.com/Q/Why_is_mass_more_useful_than_weight_for_measuring_matter
http://en.wikipedia.org/wiki/Density
http://en.wikipedia.org/wiki/Volume
Friday, October 22, 2010
Endothermic Reaction Video (almost)
Gabby and I did our reaction today. We made a video...but someone kindly deleted it for us! haha! O well...we will just explain it.
Our experiment called for 25ml of acetic acid and 15g of baking soda.... we didn't have that much acid, so we divided everything by 5 so we didn't have to use as much, but it was still balanced. Since we didn't use as much ingredients as the experiment called for, our results weren't very dramatic, but it still worked. The temperature went down 3-4 degrees Celsius.... and ended up being at about 18 degrees Celsius.
When we mixed everything together, we saw a few bubbles forming (a sign of a chemical reaction) and then it got colder. Again, there would have been more bubbles if we used as much ingredients as the experiment called for. Also, the acid smelled TERRIBLE!!!!! You would have seen it on our video, but apparently someone thought theirs was better :) hahaha.... just kidding!!!!
That is about it.... have a good weekend!!
Our experiment called for 25ml of acetic acid and 15g of baking soda.... we didn't have that much acid, so we divided everything by 5 so we didn't have to use as much, but it was still balanced. Since we didn't use as much ingredients as the experiment called for, our results weren't very dramatic, but it still worked. The temperature went down 3-4 degrees Celsius.... and ended up being at about 18 degrees Celsius.
When we mixed everything together, we saw a few bubbles forming (a sign of a chemical reaction) and then it got colder. Again, there would have been more bubbles if we used as much ingredients as the experiment called for. Also, the acid smelled TERRIBLE!!!!! You would have seen it on our video, but apparently someone thought theirs was better :) hahaha.... just kidding!!!!
That is about it.... have a good weekend!!
Wednesday, October 20, 2010
Endothermic Reaction
Hey everybody!! Gabby and I are doing endothermic reactions for Test 6. We will have a video posted soon of our actual experiment and all of our materials and results.
Endothermic: "within-heating" --> describes a process or reaction in which the system absorbs energy from the surroundings in the form of heat (takes in heat and doesn't produce it... so it is a cold reaction)
Materials
~ 25 ml of acetic acid
~15 g of baking soda
~ a styrofoam cup
~ a thermometer
~ stirring rod
Endothermic: "within-heating" --> describes a process or reaction in which the system absorbs energy from the surroundings in the form of heat (takes in heat and doesn't produce it... so it is a cold reaction)
Materials
~ 25 ml of acetic acid
~15 g of baking soda
~ a styrofoam cup
~ a thermometer
~ stirring rod
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