Standard+Extension

Part I: You have now mastered the material required from the previous standards. Now, you will continue your studies by exploring phase diagrams, as a way to better understand what is occurring between phases. Read the information below (i.e. Part I Information and Questions) and answer the questions. Then, get a worksheet from Miss Tangen. When you are done, take the quiz to show that you understand this material.

TAKE QUIZ HERE: https://www.quizlab.com/secured/authenticate_limited.cfm Click on "single class login", and input classword (tewinkle(#ofclass): ex. if you are in period 2, your classword is tewinkle2, Your password is first letter of name and as much of last name as fits (ex: htangen).

Part II: Next, research something related to the phases: plasma, melting points, boiling points, etc. Put the information into a presentable format: a drawing, an essay, a PowerPoint, etc.

Part I Information and Questions: by Anthony Carpi, Ph.D.  The different states of matter have long confused people. The ancient Greeks were the first to identify three classes (what we now call states) of matter based on their observations of water. But these same Greeks, in particular the philosopher Thales (624 - 545 b.c.), incorrectly suggested that since water could exist as a solid, liquid, or even a gas under natural conditions, it must be the single principal element in the universe from which all other substances are made. We now know that water is not the fundamental substance of the universe; in fact, it is not even an element.  To understand the different states in which matter can exist, we need to understand something called the Kinetic Molecular Theory of Matter. Kinetic Molecular Theory has many parts, but we will introduce just a few here. One of the basic concepts of the theory states that atoms and molecules possess an energy of motion that we perceive as temperature. In other words, atoms and molecules are constantly moving, and we measure the energy of these movements as the temperature of the substance. The more energy a substance has, the more molecular movement there will be, and the higher the perceived temperature will be. An important point that follows this is that the amount of energy that atoms and molecules have (and thus the amount of movement) influences their interaction with each other. Unlike simple billiard balls, many atoms and molecules are attracted to each other as a result of various intermolecular forces such as hydrogen bonds, van der Waals forces, and others. Atoms and molecules that have relatively small amounts of energy (and movement) will interact strongly with each other, while those that have relatively high energy will interact only slightly, if even at all, with others.  How does this produce different states of matter? Atoms that have low energy interact strongly and tend to “lock” in place with respect to other atoms. Thus, collectively, these atoms form a hard substance, what we call a solid. Atoms that possess high energy will move past each other freely, flying about a room, and forming what we call a gas. As it turns out, there are several known states of matter; a few of them are detailed below.   Solids are formed when the attractive forces between individual molecules are greater than the energy causing them to move apart. Individual molecules are locked in position near each other, and cannot move past one another. The atoms or molecules of solids remain in motion. However, that motion is limited to vibrational energy; individual molecules stay fixed in place and vibrate next to each other. As the temperature of a solid is increased, the amount of vibration increases, but the solid retains its shape and volume because the molecules are locked in place relative to each other.   Liquids are formed when the energy (usually in the form of heat) of a system is increased and the rigid structure of the solid state is broken down. In liquids, molecules can move past one another and bump into other molecules; however, they remain relatively close to each other like solids. Often in liquids, intermolecular forces (such as the hydrogen bonds shown in the animation below) pull molecules together and are quickly broken. As the temperature of a liquid is increased, the amount of movement of individual molecules increases. As a result, liquids can “flow” to take the shape of their container but they cannot be easily compressed because the molecules are already close together. Thus liquids have an undefined shape, but a defined volume. When we look closely we see that liquid water is made up of molecules that can freely move past one another, yet remain relatively close in distance to each other.   Gases are formed when the energy in the system exceeds all of the attractive forces between molecules. Thus gas molecules have little interaction with each other beyond occasionally bumping into one another. In the gas state, molecules move quickly and are free to move in any direction, spreading out long distances. As the temperature of a gas increases, the amount of movement of individual molecules increases. Gases expand to fill their containers and have low density. Because individual molecules are widely separated and can move around easily in the gas state, gases can be compressed easily and they have an undefined shape. <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';">Plasmas are hot, ionized gases. Plasmas are formed under conditions of extremely high energy, so high, in fact, that molecules are ripped apart and only free atoms exist. More astounding, plasmas have so much energy that the outer electrons are actually ripped off of individual atoms, thus forming a gas of highly energetic, charged ions. Because the atoms in plasma exist as charged ions, plasmas behave differently than gases, thus representing a fourth state of matter. Plasmas can be commonly seen simply by looking upward; the high energy conditions that exist in stars such as our sun force individual atoms into the plasma state. <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';">As we have seen, increasing energy leads to more molecular motion. Conversely, decreasing energy results in less molecular motion. As a result, one prediction of Kinetic Molecular Theory is that if we continue to decrease the energy (measured as temperature) of a substance, we will reach a point at which all molecular motion stops. The temperature at which molecular motion stops is called absolute zero and has been calculated to be -273.15 degrees Celsius. While scientists have cooled substances to temperatures close to absolute zero, they have never actually reached absolute zero. The difficulty with observing a substance at absolute zero is that to “see” the substance, light is needed, and light itself transfers energy to the substance, thus raising the temperature. Despite these challenges, scientists have recently observed a fifth state of matter that only exists at temperatures very close to absolute zero. <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';">Bose-Einstein Condensates represent a fifth state of matter only seen for the first time in 1995. The state is named after Satyendra Nath Bose and Albert Einstein who predicted its existence in the 1920’s. B-E condensates are gaseous superfluids cooled to temperatures very near absolute zero. In this weird state, all the atoms of the condensate attain the same quantum-mechanical state and can flow past one another without friction. Even more strangely, B-E condensates can actually “trap” light, releasing it when the state breaks down. <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';">Several other less common states of matter have also either been described or actually seen. Some of these states include liquid crystals, fermionic condensates, superfluids, supersolids and the aptly named strange matter. <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';"> Open this in a separate browser and refer to it during this reading: http://phases.wikispaces.com/extension+pics <span style="font-family: 'Arial','sans-serif';">The transformation of one state of matter into another state is called a phase transition. The more common phase transitions even have names; for example, the terms melting and freezing describe phase transitions between the solid and liquid state, and the terms evaporation and condensation describe transitions between the liquid and gas state. Phase transitions occur at very precise points, when the energy (measured as temperature) of a substance in a given state exceeds that allowed in the state. For example, liquid water can exist at a range of temperatures. Cold drinking water may be around 4ºC. Hot shower water has more energy and thus may be around 40ºC. However, at 100°C under normal conditions, water will begin to undergo a phase transition into the gas phase. At this point, energy introduced into the liquid will not go into increasing the temperature; it will be used to send molecules of water into the gas state. Thus, no matter how high the flame is on the stove, a pot of boiling water will remain at 100ºC until all of the water has undergone transition to the gas phase. The excess energy introduced by a high flame will accelerate the liquid-to-gas transition; it will not change the temperature. The heat curve below illustrates the corresponding changes in energy (shown in calories) and temperature of water as it undergoes a phase transition between the liquid and gas states. <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';">As can be seen in the graph to the right, as we move from left to right, the temperature of liquid water increases as energy (heat) is introduced. At 100ºC, water begins to undergo a phase transition and the temperature remains constant even as energy is added (the flat part of the graph). The energy that is introduced during this period goes toward breaking intermolecular forces so that individual water molecules can “escape” into the gas state. Finally, once the transition is complete, if further energy is added to the system, the heat of the gaseous water, or steam, will increase. <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';">This same process can be seen in reverse if we simply look at the graph above starting on the right side and moving left. As steam is cooled, the movement of gaseous water molecules and thus temperature will decrease. When the gas reaches 100ºC, more energy will be lost from the system as the attractive forces between molecules reform; however the temperature remains constant during the transition (the flat part of the graph). Finally, when condensation is complete, the temperature of the liquid will begin to fall as energy is withdrawn. <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';">Phase transitions are an important part of the world around us. For example, the energy withdrawn when perspiration evaporates from the surface of your skin allows your body to correctly regulate its temperature during hot days. Phase transitions play an important part in geology, influencing mineral formation and possibly even earthquakes. And who can ignore the phase transition that occurs at about -3ºC, when cream, perhaps with a few strawberries or chocolate chunks, begins to form solid ice cream. <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';">Please answer the following questions about the reading. They are not in the same order as the reading so if you are trying to skim for answers… stop… and go back and read this handout. Once you have read the entire handout then attempt to answer the questions. Answer them in your journal. <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';"> <span style="font-family: 'Arial','sans-serif';"> Solid: <span style="font-family: 'Arial','sans-serif';"> Liquid: <span style="font-family: 'Arial','sans-serif';"> Gas: <span style="font-family: 'Arial','sans-serif';"> Plasma: <span style="font-family: 'Arial','sans-serif';">
 * <span style="font-family: 'Arial','sans-serif';">Solids **
 * <span style="font-family: 'Arial','sans-serif';">Liquids **
 * <span style="font-family: 'Arial','sans-serif';">Gases **
 * <span style="font-family: 'Arial','sans-serif';">Plasmas **
 * <span style="font-family: 'Arial','sans-serif';">Bose-Einstein Condensates **
 * <span style="font-family: 'Arial','sans-serif';">Less Common States of Matter **
 * <span style="font-family: 'Arial','sans-serif';">Phase Transitions **
 * <span style="font-family: 'Arial','sans-serif';">Q1: **<span style="font-family: 'Arial','sans-serif';"> What is the hottest temperature liquid water can exist at?
 * <span style="font-family: 'Arial','sans-serif';">Q2: **<span style="font-family: 'Arial','sans-serif';"> What happens to individual molecules as they enter the plasma state?
 * <span style="font-family: 'Arial','sans-serif';">Q3: **<span style="font-family: 'Arial','sans-serif';"> What is a Bose – Einstein Condensate? What temperatures do they exist near?
 * <span style="font-family: 'Arial','sans-serif';">Q4: **<span style="font-family: 'Arial','sans-serif';"> What is the Kinetic Molecular Theory?
 * <span style="font-family: 'Arial','sans-serif';">Q5: **<span style="font-family: 'Arial','sans-serif';"> For each of the following states of matter, compare the strength of the atoms attractive forces to the energy causing them to pull apart.
 * <span style="font-family: 'Arial','sans-serif';">Q6: **<span style="font-family: 'Arial','sans-serif';"> What is the actual value of absolute zero in °C?
 * <span style="font-family: 'Arial','sans-serif';">Q7: **<span style="font-family: 'Arial','sans-serif';"> Why does the temperature remain constant as a substance changes from one phase to the next?