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=Study Guide= GQ 1 and GQ 2 Matter Definition Types of matter States of matter Properties of matter: characteristic properties Changes in matter

Periodic Table Atoms Structure of atoms Parts of the atom Structure of the Periodic Table Molecules Compounds Types of Bonds

Review all of the assignments listed in the Study Guide

= = =GQ:1 Melting Point = Problem: How does the Temperature of the Surrounding affect the rate at which ice melts? What We Need to Know: Our experiment covers concepts such as characteristic property, chemical changes and physical changes .The characteristic property our experiment had is melting point. The melting point is at 0°C 32°F. We also studied physical and chemical changes. A chemical change is one or more substances combine or break apart to form new substances. And a physical change alters the form of a substance, but not it’s identity. Hypothesis: Our hypothesis is the warmer the surrounding area is, the faster the ice will melt. Experiment: To test our hypothesis we had two cups of tap water, one at 40° c and the other at 21°c. We then placed one ice cube in each cup and timed to see which one melted faster.

Our results were…. Yes because our prediction was the ice cube in cup one will melt faster, which is what happened.
 * || **Beginning Temperature (C°)** || **Time to Melt** || **Final Temperature (C°)** ||
 * **Cup 1** || 40° C || 1:30.01 || 27° C ||
 * **Cup 2** || 21° C || 2:35.09 || 14° C ||
 * 1)** **Was your prediction in step one supported by the results of the experiment? Explain why or why not.**

Cup one changed the most. Its temperature at first was 40 degrees Celsius and the end temperature was 27 degrees Celsius; and the temperature of cup two was 21 degrees Celsius at first and the end temperature was 14 degrees Celsius.
 * 2) In which cup did the water temperature change the most? Explain the result.**

The ice took the heat of the water which was what gained enough energy to overcome the force holding the ice together.
 * 3) When the ice melted, its molecules gained enough energy to overcome the forces holding them together as solid ice. What is the source of the energy?**

It was hard to time the exact moment each ice melted because we are human. We make mistakes because we can't just stare at the ice the whole time and see if it melted while we're timing it. Also we couldn't guarantee that the temperature we started with would sustain. Errors in measurements can affect our conclusion because if we made a mistake timing, it could make our prediction wrong, and change our conclusion.
 * 4) How well could you time the exact moment each ice cube completely melted? How might errors in measurements affect your conclusion?**

Conclusions: Our conclusion was that the temperature affected how fast the ice cube melted and the ice cube in the warmer water melted faster than the one in the colder wa 1)  **Our hypothesis was the bigger the atomic number is, the bigger the radius will be.
 * GQ:2 Comparing Atom Sizes
 * Our problem was: How is the radius of an atom related to its atomic number? **

Our conclusion was that our hypothesis was right. The bigger the atomic number, the bigger the radius will be.
 * For our experiment we needed to know the atomic numbers, radius, and **
 * relative radiuses of each of the atoms listed on our sheet. **
 * For our experiment we figured out the radius of an atom related to its atomic number. To do this we calculated the relative radius of each atom compared to beryllium. We used a compass and drew a circle for each element with a radius that corresponds to the relative radius we calculated. **
 * Our results were: **
 * ** Atomic Number ** || ** Element ** || ** Radius (pm) ** || ** Relative Radius ** ||
 * 4 || Be || 112 || 1 ||
 * 12 || Mg || 160 || 1.4 ||
 * 20 || Ca || 197 || 1.8 ||
 * 38 || Sr || 215 || 1.9 ||
 * 56 || Ba || 222 || 2 ||

1) Based on your models, was your prediction in Step 1 correct? Explain your answer. Yes, our prediction in Step 1 was correct. Our prediction was the bigger the atomic number is, the bigger the radius will be. 3) Do your graph points fall on a straight line or on a curve? What pattern does your graph show? The points on our graph steadily increase with the atomic number. So this means that it is on a curve. 4) Predict where you would fine the largest atom in the chemical family. What evidence would you need to tell if your prediction is correct? We predict that the largest atom in a chemical family would be higher on the graph then the following atom. The evidence we would need to tell if our prediction was correction is the atomic number, radius, and relative radius. 5) If an atom has an actual radius of 100 to 200 Picometers, why would drawing a model with a radius of about one to two centimeters be useful? It would be useful because you would use centimeters as a scale for the picometers.

Testing 1, 2, 3 Problem: How does copper compare to graphite?

Hypothesis: Copper is a metal. Metals are shiny, a conductor for electricity and malleable. Graphite isn’t a metal because it contains carbon. Graphite is dull, a resister and brittle.

Part 1: Physical Properties (comparing the two samples) The copper is gold and shiny, while the graphite is dull and grey. When we bent the copper it twisted easily while the graphite just broke in half.

Part 2: Electrical Conductivity (learning which material is a conductor by seeing which made the light bulb light up.) When the copper piece touched the battery, it lit the light bulb so metal is a conductor. The graphite is a resister and didn’t light the light bulb.

Part 3: Heat Conductivity (seeing which material got hot) We put the copper wire and the lead into the hot water at the same time. The copper got hot in a minute and a half, while the lead never got hot. This also showed that metal is a conductor while graphite is a resister.

__Analyze and Conclude__ The copper is gold and shiny, while the graphite is dull and grey. When we bent the copper it twisted easily while the graphite just broke in half.
 * 1) Compare the physical properties of copper and graphite that you observed.

The graphite was a resister and didn’t get hot in the water or turn on the light, while the copper was a conductor and became hot fast and turned on the light.
 * 1) Describe the results of the electrical conductivity and heat conductivity tests that you performed.

Copper is a metal. Metals are shiny, a conductor for electricity and malleable. Graphite isn’t a metal because it contains carbon. Graphite is dull, a resister and brittle.
 * 1) Based on the observations you made in this lab, explain why copper in classified as a metal and carbon is not classified as a metal.

It was important for the lengths to be equal so that the heat wouldn’t have a farther length to travel.
 * 1) In step 11, why was it important to use equal lengths of copper wire and graphite.

Graphite is good for pencil lead or antiflammable materials because it is a resister, while copper would be good for a pot because it heats up quickly and is a conductor.
 * 1) Based on your observations and conclusions from this lab, for what products might copper and graphite be best suited?

__Problem__- How does the volume of a gas change as the pressure you exert increases?

__What you need to know__- Gas particles spread apart, filling all the space available to them. Gases squeeze air together or spread out. You can squeeze gas together. For example, an oxygen tank is compressed air. Though, a gas doesn’t have volume nor complete shape.

__It a gas

Experiment__- For our experiment we needed a plastic syringe that at the bottom had a ball of clay on it. The reason for that being is because we needed to see how low the syringe would go if, for example, we had two books on the top of it, or taking. Basically, our experiment consisted of finding out how many books it took to compress the gas.

__Materials__ Plastic syringe (with no needle), at least 35cm3 capacity Modeling clay 4 books of uniform weight __1 Hypothesis__ Our hypothesis is that when more books are put on and the more force that is compressed in the plastic syringe, the less volume it will take up.

__2 Hypothesis__ Our hypothesis for when books are taken of is that the more force that is taken off the plastic syringe, the more volume it will take up.

__Conclusion__ Our conclusion was that when putting the books on the syringe the more force was compressed in the plastic syringe, the least volume it will took up. When taking the books off the syringe the more force that is taken off the plastic syringe, the more volume it will take up. __Analyze and Conclude__ 1) Make graph. 2) Make graph. 3) Did the results you obtained support your predictions in Steps 6 and 9? Explain. Yes. The results in Steps 6 and 9 did support are predictions because when putting the books on the syringe the more force was compressed in the plastic syringe, the least volume it will take up. When taking the books off the syringe the more force that is taken off the plastic syringe, the more volume it will take up. 4) The relationship to the volume and pressure of a gas in graph number one is shown when putting the books on the syringe the more force was compressed in the plastic syringe, the least volume it will take up. 5) The two graphs compare to each other because the more weight that is put on the syringe the more compressed the gas will be.

Shedding Light on Chemical Bonds By: Lily, Susanne, and James

1) Why did you test the plain water first? We tested the plain water first because we wanted to see if the water had any reactions to the electric bonds, and because it is a conductor of electricity. 2) Based on your observations, indicate wither each substance tested contained ionic or covalent bonds. The water had covalent bonds and didn’t have any reactions, the salt had ionic bonds. The wire ended up melting when in the liquid after about an hour. 3) Explain why one substance is a better conductor of electricity than another. The water isn’t as good as a conductor because it is has covalent bonds and the salt had ionic bonds. 4) Did all the substances that conducted electricity show the same amount of conductivity? How do you know? No, because the water made the electricity flow covalent and the salt made the electricity flow ionic.

Hypothesis Our hypothesis was that the water would have covalent bonds and not react to the metal because they are poor conductors of electricity. The salt would have an ionic bond and react to the metal because they are good conductors of electricity.