Histamine is a potent vasodilator. It has various functions. It basically contracts the smooth muscles in the bronchi and gut and relaxes other muscles. Histamine is also responsible for the nasal congestion caused by common cold and allergic response to pollen. The permeability of white blood cells is increased by histamine and this allows the … Read more

The revolution in medical field in the form of antibiotics has provided people with long and healthy life to people. The life expectancy has almost doubled. This increase in the population has led to many social problems in terms of food resources, environmental issues, employment, etc. To control these problems, population is required to be … Read more

Initially Antibiotics were thought about as antimicrobial drugs obtained from other organisms (such as moulds, fungus and some soil bacteria) to combat harmful microorganisms. The synthetic methods have helped in synthesizing some of the compounds that were originally discovered as products of microorganisms. Some purely synthetic compounds also have antibacterial activity, and because of this, … Read more

Antacids are bases which are generally used to neutralize the acid that causes heartburn. Hyperacidity i.e. when stomach produce too much of acid, leads to heartburn. Almost all antacids neutralises the excess stomach acid with weak bases. The most common of these bases are hydroxides, carbonates, or bicarbonates. The table shows reactions by which these antacids … Read more

When a household solid waste is dumped at the dumpsite, then a part of that waste is disappeared after few days that is the biodegradable waste and some waste starts accumulating at that place, that is the non-biodegradable waste. The solid substances which are decomposed after few days contain some of the polymers that are … Read more

p-Block Elements: Group 18 Uses Although noble gases are unreactive, they are still very useful elements. Many uses of noble gases depend on their ability to prevent other, undesirable, reactions taking place. Helium is less dense than air, so it’s great for all kinds of balloons. Helium balloons are capable of lifting instruments into the … Read more

p-Block Elements: Group 18 Physical and chemical properties All noble gases are colourless, odourless and unreactive. This makes it difficult to isolate and identify. Nowadays, a number of compounds of these gases, particularly of xenon and krypton have been prepared, this shows that these gases are not completely inert. They are also called rare gases … Read more

p-Block Elements: Group 18 Occurrence All the noble gases except radon occur as monoatomic gases in the atmosphere. These are the only gases in earth’s atmosphere that are monoatomic since most other gases are diatomic. Together they make up 1wt After Hydrogen H, Helium (He) is the second most abundant element in the universe although … Read more

p-Block Elements: Group 18 Electronic configuration All noble gases have full outer electron shells and do not need to gain, lose or share electrons. This means that: They are very stable and the most unreactive (or inert) of all the elements. They do not normally form bonds with other elements. They are monatomic, which means … Read more

p-Block Elements: Group 18 General Introduction The Group 18 elements are called noble gases or inert gases because they rarely combine with other elements. They are found only as uncombined elements in nature and some compounds. Nobel gases are colourless at room temperature. Only neon and helium are not yet prepared from their compounds. The … Read more