In the form of edible or table salt it is commonly used as a condiment and food preservative. Large quantities of sodium chloride are used in many industrial processes, and it is a major source of sodium and chlorine compounds used as feedstocks for further chemical syntheses.n the language of close-packing, the larger chloride ions are arranged in a cubic array whereas the smaller sodium ions fill all the cubic gaps (octahedral voids) between them. This same basic structure is found in many other compounds and is commonly known as the halite or rock-salt crystal structure.
1 Most dental schools are 4 years, a few are 3. About half of the orthodontic schools are 2 years and the rest are 3 years. 2  it takes 4 years of undergraduate education (usually, it can take 2-3 if you have exceptional credentials) and then 3-4 years in dental school (depending on a particular schools curriculum).
Doctors in the United States spend many years acquiring the necessary education and skills to practice medicine. The preparation for medical school usually begins in high school. Beyond high school, medical training last through four typical periods: undergraduate education, medical school, residency and fellowship. If a physician chooses to complete a lengthy fellowship, her education may take 15 year or longer from the time she first enters college. Undergraduate Studies To become a doctor, a student must first complete high school, then go on to college. During the typical four-year undergraduate period, the aspiring doctor will study topics such as anatomy, physiology, biology, chemistry and other college courses necessary for a degree, such as English or math.