Science & Technology
1-The densest form of Carbon is diamond.
2-Graphite is used as a lubricant because it is soft and greasy.
3-The role of a catalyst in a chemical reaction is to change the activation energy.
4-The four covalent bonds of a carbon atom are arranged in the shape of a regular tetrahedron.
5-In the process of electrolysis, the positive and negative ions of electrolyte are discharged.
6-Distilled water is made by the process of evaporation followed by condensation.
7-Water exists both as solid and liquid at 0 degree centigrade.
8-Calgon is the trade name of Sodium hexametaphosphate.
9-Permutit is the name for sodium aluminium orthosilicate
10-The solubility of gases in liquids can be increased by decreasing temperature and increasing pressure.
11-Hard water does not lather with soap owing to the formation of stearates of Calcium and Magnesium.
12-Ammonia is highly soluble in water since its molecules are markedly polar.
13-Fixation of nitrogen refers to conversion of atmospheric nitrogen into nitrogen compounds.
14-The rocky material present in an ore is called gangue.
15-A substance used in metallurgy to remove rock material is called flux.
16-Duralumin is an alloy containing Magnesium, Copper,Manganese and Aluminium.
17-Nitrogen pentoxide contains only covalent bonds.
18-The most characteristic property of metals is their tendency to lose electrons.
19-An ammonium compound which sublimes on heating is Ammonium Chloride.
20-The amount of Hydrogen in water by mass is 11.11 percent.