Emotion Emotion is one type of affect, other types being mood, temperament and sensation for example, pain. Emotions can be understood as either states or as processes.
Water is a substance that is in great abundance on this planet, and it holds some significant importance to our lives. Without it, we could not live, and not simply because we would die of thirst. Some of the notes here are also relevant to AS Chemistry, but be careful, as different specifications might ask for information on different anomalous properties, so make sure you check your exam syllabus!
The Properties of Water Water is a dipolar molecule: A water molecule consists of two hydrogen atoms and an oxygen atom; however, the electrons in the covalent bonding are not shared equally. The oxygen atom has a greater electronegativity, meaning that it has a greater pull on the electrons.
Due to this each water molecule has slightly negative and slightly positive regions. Water molecules form hydrogen bonds: The negative and positive ends of water molecules attract each other to form hydrogen bonds. These hydrogen bonds give water many of its unique properties.
Compounds with molecules similar to the size of water are usually gases. Since each water molecule can form hydrogen bonds with up to 4 other water molecules, water is a liquid at room temperature. Water is the universal solvent: Polar and ionic substances have an electrostatic charge, so they are attracted to the charges on water molecules and dissolve readily.
Non-polar substances, such as oil, do not dissolve in water, as they do not have charged molecules. When a salt dissolves in water, the ions separate and a layer of water molecules form around the ions. These layers prevent ions or polar molecules from clumping together, keeping the particles in solution.
Water has a high surface tension: At an interface between air and water, a water molecule on the surface forms hydrogen bonds with other molecules around and below it, but not with air molecules above it.
Ice floats on water: Water is at its most dense at 4oC. When water freezes the hydrogen bonds between the molecules forms a rigid lattice, that holds the molecules further apart then in liquid water. Ice, having expanded when freezing, is less dense than its liquid counterpart and so floats on water.
Water is adhesive and cohesive: This is because its molecules can form hydrogen bonds with other polar substances. This is called adhesion.
The attraction between molecules of similar substances is called cohesion. In this way water molecules stick together which allows water to enter and move along very narrow spaces, in a process called capillarity. Water has a high specific heat capacity meaning that it needs to gain a lot of energy to raise its temperature.
Conversely it also needs to lose a lot of energy to lower its temperature. Water also has a high latent heat of fusion meaning that at 0oC water must lose a lot of thermal energy before it freezes, thus liquid water can reach temperatures of down to oC before it forms ice.
Other physical properties of water: It is transparent to sunlight. It has a relatively high density compared to air. It is difficult to compress. It conducts electricity when it contains dissolved ions See if you can think of ways that these properties are important to life.
An important part of A Level Biology is being able to write a clear and concise essay on the topics you have covered, particularly as many exam boards set an essay question in each of their papers.The Role of Water in Living Organisms Essay - Water is essential to life, without water life on Earth would not exist.
Water is a major component of cells, typically forming . Revision:The Role of Water to Living Organism - Essay Plan Water is a solvent for numerous biochemical moleculesm giving solutions and enabling: Transport of nutrients, e.g.
glucose and amino acids in blood, and sucrose in phloem.
Theories of Emotion. There are different theories of emotion to explain what emotions are and how they operate. This is challenging, since emotions can be analyzed from many different perspectives.
Jun 01, · Order your The roles of water in living organisms,and as an environment for organisms. paper at affordable prices with Live Paper Help! Water is vital to life, with out water life on earth would cease to exist as every living organism must have water in order to survive.
Biology: Biology, study of living things and their vital processes that deals with all the physicochemical aspects of life. Modern principles of other fields, such as chemistry, medicine, and physics, for example, are integrated with those of biology in areas such as biochemistry, biomedicine, and biophysics.
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