What is the valency of carbon?

The valency of carbon is 4. The valency of an element measures its ability to combine with other elements. The valency is determined by the number of electrons in the outer shell of each atom of an element.

Question Asked on Nov. 17, 2016, 6:19 p.m. by Abhinav Read more

As though hydrogen and oxygen are in gaseous form how come water(H2O) exist in liguid form?

Hydrogen of one molecule of water is bound to highly electronegative oxygen of another water molecule. This gives rise to a highly attractive electromagnetic interaction, called hydrogen bond. Thus, extensive intermolecular hydrogen bonding is responsible for higher than expected boiling point of water, making it a liquid at room conditions.

Question Asked on Feb. 18, 2016, 9:46 p.m. by SIRAJUL ULOOM Read more

what is chromium ?

Chromium is a chemical element with symbol $Cr$ and atomic number $24$. It is the first element in Group $6$. It is a steely-gray, lustrous, hard and brittle metal which takes a high polish, resists tarnishing, and has a high melting point. Electron configuration: $ [Ar] 3d^{5}4s^{1}$

Question Asked on Jan. 9, 2016, 7:34 p.m. by Gayathri ASHOK Read more

Why elements in the number of third period is 8 ?

Question Asked on Dec. 27, 2015, 2:14 p.m. by Meenakshy. S Read more

When turmeric stain gets on a white cloth & the cloth is cleaned with soap, the stain becomes red. Why? How can one remove the red stain?

Turmeric is an natural colour indicator because it changes its colour in acid medium as well as in base medium.

When turmeric is combined with any base liquid like it turns red in colour while when turmeric comes in contact with any substance like that of vinegar, that is acidic in nature, it turns yellow.

The following are a few ways that can be applied in removing turmeric stains from fabric.

Dry Detergent

This method can be used for both colour and whites. Rub the stain with a dry detergent bar and allow it to set ...

Question Asked on Nov. 18, 2015, 8:22 p.m. by Annie Read more

Who invented plastic ?

The first man-made plastic was created by Alexander Parkes who publicly demonstrated it at the 1862 Great International Exhibition in London. The material called Parkesine was an organic material derived from cellulose. The first truly synthetic plastic was invented by Leo Baekeland – a Belgium chemist living in New York.

Question Asked on Sept. 15, 2015, 8:57 p.m. by gowri Read more

How will separate a mixture of iron filings, sand and common salt ?

Use a magnet to remove the iron filings first. Then pour boiling water into the sand/salt mixture and stir it until the salt is dissolved. Filter off the sand and set it aside, then boil the salt water until the water evaporates or leave it in an evaporating basin.

Question Asked on Sept. 12, 2015, 12:40 p.m. by Anu Read more

What is Distillation?

Distillation is a widely used method for separating mixtures based on differences in the conditions required to change the phase of components of the mixture. To separate a mixture of liquids, the liquid can be heated to force components, which have different boiling points, into the gas phase. The gas is then condensed back into liquid form and collected. Repeating the process on the collected liquid to improve the purity of the product is called double distillation.

           Although the term is most commonly applied to liquids, the reverse process can be used to separate gases by liquefying components using changes ...

Question Asked on Sept. 12, 2015, 12:37 p.m. by Anu Read more

How is common salt obtained from sea?

The evaporation method depends on the geographical area and whether the saltwater is processed in large or small batches.

           In drier areas, sea salt is harvested by exposing it to the sun and air in short-depth pools. If the air is too humid, the water will not evaporate as easily. Once all the water has evaporated, the salt is collected by harvesters. More often, seawater is processed commercially through vacuum pans, though the water is still evaporated away from the salt. In this process, it is evaporated by boiling the water off rather than through the heat of the sun.

Question Asked on Sept. 12, 2015, 12:37 p.m. by Anu Read more

LIQUID FUEL USED IN HOMES IS KEROSENE OR LPG

Both are liquid fuels. And both are used in homes.

Question Asked on Sept. 5, 2015, 11:34 a.m. by gowri Read more