Snowflake Chemistry - Common Questions

Snowflake Chemistry - Common Questions Have you ever looked at a snowflake and wondered how it formed or why it looks different from other snow you might have seen? Snowflakes are a particular form of water ice. Snowflakes form in clouds, which consist of water vapor. When the temperature is 32 ° F (0 ° C) or colder, water changes from its liquid form into ice. Several factors affect snowflake formation. Temperature, air currents, and humidity all influence shape and size. Dirt and dust particles can get mixed up in the water and affect crystal weight and durability. The dirt particles make the snowflake heavier  and can cause cracks and breaks in the crystal and make it easier to melt. Snowflake formation is a dynamic process. A snowflake may encounter many different environmental conditions, sometimes melting it, sometimes causing growth, always changing its structure. Key Takeaways: Snowflake Questions Snowflakes are water crystals that fall as precipitation when its cold outside. However, sometimes snow falls when its slightly above the freezing point of water and other times freezing rain falls when the temperature is below freezing.Snowflakes come in a variety of shapes. The shape depends on the temperature.Two snowflakes can look identical to the naked eye, but they will be different on the molecular level.Snow looks white because the flakes scatter light. In dim light, snow appears pale blue, which is the color of a large volume of water. What Are Common Snowflake Shapes? Generally, six-sided hexagonal crystals are shaped in high clouds; needles or flat six-sided crystals are shaped in middle height clouds, and a wide variety of six-sided shapes are formed in low clouds. Colder temperatures produce snowflakes with sharper tips on the sides of the crystals and may lead to branching of the snowflake arms (dendrites). Snowflakes that grow under warmer conditions grow more slowly, resulting in smoother, less intricate shapes. 32-25 ° F - Thin hexagonal plates25-21 ° F - Needles21-14 ° F - Hollow columns14-10 ° F - Sector plates (hexagons with indentations)10-3 ° F - Dendrites (lacy hexagonal shapes) The shape of a snowflake depends on the temperature at which it formed. 221A / Getty Images Why Are Snowflakes Symmetrical (Same on All Sides)? First, not all snowflakes are the same on all sides. Uneven temperatures, presence of dirt, and other factors may cause a snowflake to be lop-sided. Yet it is true that many snowflakes are symmetrical and intricate. This is because a snowflakes shape reflects the internal order of the water molecules. Water molecules in the solid state, such as in ice and snow, form weak bonds (called hydrogen bonds) with one another. These ordered arrangements result in the symmetrical, hexagonal shape of the snowflake. During crystallization, the water molecules align themselves to maximize attractive forces and minimize repulsive forces. Consequently, water molecules arrange themselves in predetermined spaces and in a specific arrangement. Water molecules simply arrange themselves to fit the spaces and maintain symmetry. Is It True that No Two Snowflakes Are Identical? Yes and no. No two snowflakes are exactly identical, down to the precise number of water molecules, spin of electrons, isotope abundance of hydrogen and oxygen, etc. On the other hand, it is possible for two snowflakes to look exactly alike and any given snowflake probably has had a good match at some point in history. Since so many factors affect the structure of a snowflake and since a snowflakes structure is constantly changing in response to environmental conditions, it is improbable that anyone would see two identical snowflakes. If Water and Ice Are Clear, then Why Does Snow Look White? The short answer is that snowflakes have so many light-reflecting surfaces they scatter the light into all of its colors, so snow appears white. The longer answer has to do with the way the human eye perceives color. Even though the light source might not be truly white light (e.g., sunlight, fluorescent, and incandescent all have a particular color), the human brain compensates for a light source. Thus, even though sunlight is yellow and scattered light from snow is yellow, the brain sees snow as white because the whole picture received by the brain has a yellow tint that is automatically subtracted. Sources Bailey, M.; John Hallett, J. (2004). Growth rates and habits of ice crystals between −20 and −70C. Journal of the Atmospheric Sciences. 61 (5): 514–544. doi:10.1175/1520-0469(2004)0610514:GRAHOI2.0.CO;2 Klesius, M. (2007). The Mystery of Snowflakes. National Geographic. 211 (1): 20. ISSN 0027-9358 Knight, C.; Knight, N. (1973). Snow Crystals. Scientific American, vol. 228, no. 1, pp. 100-107. Smalley, I.J. Symmetry of Snow Crystals. Nature 198, Springer Nature Publishing AG, June 15, 1963.

Fourth Grade School Supplies List

Fourth Grade School Supplies List In the fourth grade, students begin to establish a foundation for developing research skills, writing skills, and critical reading skills. The supplies listed here are typical of the tools students will use to learn fourth grade skills. As always, you should check with your teacher to determine the specific supplies youll need. No. 2 Pencils Students will go through many pencils and erasers in the fourth grade, so it is important to keep a full supply in the home.Eraser packs Dont be caught unprepared!Planner Time management skills are important for success in the fourth grade, as students often find homework assignments require a bit more organization and planning than ever before.Colored pocket folders Teachers often require separate folders for individual subjects.Binder In the fourth grade, subjects may be separated in a binder. Some teachers encourage students to keep time management aids in binders.Wide-ruled paper This type of paper is often required for essay assignments.Highlighters Students begin to use highlighters to mark important information on study sheets and notes.Red pens In the fourth grade, students may start to switch papers for grading. Red pens and pencils are used for grading other students assignments.Pencil box Its important to stay organized.Backpack Many schools require students to use clear backpacks. Pencil sharpener Youll need one for test day!Bookmarks Youll be reading more advanced books.Colored pencils Students begin to study geography in the fourth grade in much greater detail. Colored pencils will be used for maps and other projects.Ruler Students begin to work with graphs in the fourth grade. Geometry is also a subject students will explore in some depth.Flashcards Students begin to learn concepts in math such as order of operations. It is important for students to fully memorize multiplication tables.

Developing an Implementation Plan Essay Example | Topics and Well Written Essays - 1250 words

Developing an Implementation Plan - Essay Example Also, in order to attract support from staff members, lobbying will be applied as necessary. Description of the Current Problem Requiring Change People have used exercise in as a measure against coronary heart disease. However how effective exercise is in reducing the risk of suffering coronary heart disease is still at question? Exercise has been known to be an important component in the well-being of any individual. Most studies have suggested that exercise is very crucial in the prevention of most life’s problems and keeping the body in its optimal condition. Despite its eminent benefits, exercise can be detrimental if done wrongly. However, in cases of cardiovascular disease, controversies have risen on the amount of exercise required to prevent this risk and treat patients with this condition. The current United States guidelines recommend that adults should seek at least moderate-level exercise for more than or equal to 150 minutes per week, that is, 30 minutes in a day for five days in a week. Though this is the recommended time to achieve the best from exercise, several studies have suggested different times for performing exercise. Thus, the change proposed is that it must be ensured that the individual gets optimal exercise depended on the severity of the problem, age, and gender. For instance, a study found that brisk walking more than ten blocks away in a day reduced the risk of cardiovascular disease in women. It is also suggested that different forms of exercise should be adopted for various people. Detailed Explanation of the Proposed Solution Optimal exercise activity is crucial for the well-being of any individual. However, not at all times will the recommended time for exercise work for individuals. Most individuals are of the notion that exercise should be intense to obtain the best from the exercise. However, this is not true in all cases and thus the notion should be disregarded. In the case of patients with cardiovascular disease, t he severity of the condition, age, and gender will determine the amount of exercise to be done by the individual. Thus, this statement defeats the notion that exercise should at least be done for 30 minutes in a day for five days in a week. In this sense, the individual should exercise based on the severity of their condition, age, and gender. What this means is that every patient suffering from coronary should not be subjected to over exercise. Performing strenuous exercises may result in greater damage than good as stated by different experts. In a bid to establish the extent to which exercise can be useful to coronary heart disease patients, a survey will be conducted. The survey will seek to establish the kinds of exercises that the patients do regularly and how long they engage in the activities. Furthermore, the survey will seek to establish how they feel after the exercises and the notable health benefits that they gain thereafter. The respondents will comprise patients suffe ring from coronary heart disease, individuals of either gender randomly drawn from the hospital’s population. In addition to conducting a survey, interviews will be conducted with respondents being health experts directly dealing with the patients. The interviews will involve asking the respondents about the effects of exercise that patients undertake with due respect to the extent of the activity. Essentially, the study will help in