Hello and welcome to our blog! We are four students studying teacher education program at the Unive

Hello and welcome to our blog! We are four students studying teacher education program at the University of Skövde, focusing early ages. Right now, we read the course Science and Technology for early ages. In our blog we will discuss the course contents and we will also immerse ourselves in our chosen field, WATER. cnr Hope you have a pleasant reading, please leave a comment.
According to Boren, Larsson, Lif, Lillieborg and Lindh (2001), water is a substance that is composed of H 2 O molecules, ie, one oxygen atom and two hydrogen atoms. Edman and Klein (1997) writes that it is the negatively charged electrons that hold the atoms in a molecule. The hydrogen atoms have their electron and oxygen atom has six electrons in its outermost shell. For hydrogen to become stable with two electrons in the outer shell and the oxygen to be stable with eight, "borrows" the hydrogen atoms were its electron from the oxygen and the oxygen is "borrowing" from the two hydrogen atoms. In this way, they argue that there are now eight electrons spins around the three atoms and hold them together in a molecule of water. Edman and Klein writes that the electron cloud is uneven, it is thicker at the oxygen end and therefore the molecule becomes weakly electrically charged. This means that water molecules always lock together. Although Olsson (2002), writes that water is a bipolar substance, a dipole, and that this is because oxygen is most nuclear charge and attracts electrons shift to the oxygen. Olsson also believes that this is the explanation of water's unique properties.
Borén et al. (2001) argue that water is an excellent solvent and that it is therefore difficult to find completely pure water. cnr Olsson (2002) argues that water dissolves other polar substances well, such as salts. Borén et al. writes that most water comes in contact with the solution to some extent and the solutes affect the properties of water. They mean to change properties of water may be due to the binding conditions between the water molecules is disturbed by the contact with the solute molecules. An example authors provide cnr for this is that the detergent reduces the surface cnr tension, due to hydrogen bonds between the water molecules are broken.
With regard to density, type Olsson (2002) that this is the most in the water at +4 C. When liquid water turns cold molecules are packed together and the water becomes heavier and reaches its maximum density at +4 C. He also takes up the water gets less dense when it freezes. The molecules arrange themselves then in a rigid three-dimensional pattern of hexagons and it also formed voids between the molecules. He writes that this means that the water in contrast to many other substances expand when it freezes. Water as solvent
Something Borén, Bostrom, Börner, cnr Larsson, Lillieborg and Lindh (2005) points out that in nature there is no clean water, this is due to water's ability to solve various topics. Water as a solvent gives condition for human life because our body to about 66% water, Boren et al. writes that blood and lymph are some of the body's major water solutions and transporting nutrients and oxygen to the body's tissues and then carry away the waste. Parker (1990) shows that life's chemical reactions can not take place unless its organic molecules are free to move, mix and react with each other. To do so, they must be dissolved or floating in water. Water can not be replaced by any other substance as a solvent for ions and molecules as well as the medium for biochemical reactions writes National Encyclopedia (2010). Water is also involved in numerous biochemical reactions, it is consumed in plant photosynthesis and re-formed in cell respiration.
Water is the dominance of our common solvents according Boren et al. (2005). cnr A solvent properties is that it is able to solve other substances without reacting with them. Due vattenmolekylens configuration, waterless especially salts but also other substances with properties similar to water. Water can also solve various gases. National Encyclopedia (2010) highlights that this plays an important role in biological systems. Solubility of gases in water depends on temperature and pressure, increased pressure dissolves more gas and raised the temperature starts the dissolved gases rise off the air by Boren et al.
Salt dissolves in water and Borén et al. (2005) state that the oceans salinity is 3.5%, slightly lower estuary where salt water mixes with fresh water or in the Arctic, where sea water mixed with fresh water from melting ice. In warmer seas is the opposite higher salinity because cnr evaporation is higher there and when the water evaporates, the salt does not comply with. Wiklund (2000) states that the salt in the ocean comes from rocks and brought out to the sea by rivers and streams. Archimedes' principle
Andersson (2008) describes an event out