Showing posts with label science questions. Show all posts
Showing posts with label science questions. Show all posts

Common science questions and answers

Common science questions for basic knowledge -

1 • what is the name of reaction between an Acid and a base is  .

Answer. Neutralisation or Neutralization .

2 • What is Oxidation .

Answerthe loss of electrons know as a oxidation and Reduction is the gain of electrons 

3 • Which is The most conductive metal .

Answer. Silver

4 • What is Hydropower  .

Answer. In this process Hydropower create energy From the action of falling water , as water falls from a height the energy is used to turn turbines which create a electricity .

5 • What is Solar energy -

Answer. Energy produced by sun is called solar energy . the sun radiation trapped in solar panels then is turn into electricity .

6 • The First Three Alkanes are -

AnswerMethane  (  Ch4 )
                  Ethane  ( Ch3Ch3 )
                   Propane ( Ch3Ch2Ch3 ) 

7 • What is chemical bond -

Answer. the physical process where atoms and molecules to be attracted together then bound in new  compounds is called chemical bond

8 • When acid rain occurs - 

Answer. Acid rain occurs When Sulphur dioxide and nitrogen dioxide are emitted in to air . 

9 • what is Atomic mass number -

Answer. Symbol of atomic mass number is ( A )  , it is the total number of protons and neutrons in the nucleus of an atom .

10 •  what is atomic number - 

Answer. Symbol of atomic number is ( Z )  , it is the number of protons in atom .

11 •  Molar mass -

Answer. Molar mass ( M ) is the mass of one mole a chemical substance . unit of molar mass is gm/mole 

12 •  Fundamental units are there in SI System -

Answer. 7 ( seven ) ,  fundamental units in SI system .

13 • Fundamental particles of atom

Answer. Electron , proton and neutron .

14 • Formula of neutrons -

Number of neutrons = mass number - atomic number present in elements .

15 • Formula of atomic weight -

Atomic weight = no . of protons + no . of neutrons .

What is CNG

CNGCNG stands For Compressed natural gas , which can be used used  as an alternative fuel in internal combustion engines , CNG is a mixture or hydrocarbon gases and Vapours in which methane is the main Constituent . This is compressed to a very high pressure for use in automobile . Octane rating of CNG is about 120  , hence it is a far superior fuel as compared to petrol . further engine running on CNG are environmental friendly , noiseless and require almost no maintenance .
CNG as an alternative fuel for ic engine has for better future as it pollution free . it does not contain any harmful substance like nitrogen , lead , sulphur , thus there are no NOx and So2 emission , further CNG burn completely and does not produce CO and any odour nuisance .

Key point to remember

1. CNG also know as - Compressed natural gas .
2. CNG is made by compressing natural gas  ( specially composed of methane ) .
3. Octane rating of CNG about 120  .
4. Chemical formula of methane is - CH4 .
5. Compressed natural gas lighter than air .
6. CNG mainly used in gasoline , diesel fuel  .