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Question & Answer Forum

Next time you have a doubt while studying, you know where to go. By simply posting your questions on Question & Answer Forum, you can have them answered by academic experts. You can also find related videos and explanations for better understanding.

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Swathi answered 3 year(s) , 11 month(s) ago

Atomic masses of first 30 elements?

It is not possible to give the atomic masses of all the elements. Here iam giving the atomic masses of first 30 elements in the periodic table.
Element Atomic number Atomic mass Hydrogen  1 1 Hel...

Asked by Mragisha

Dec 17

  • 1 Answer
  • 23 Likes
  • 105171 Views
Vikas answered 3 year(s) , 6 month(s) ago

Acidic & basic radicals.

Ans:  
The ion formed after removal of Hydrogen ion (H⁺ ion) from an acid is called acid radical.
Ex: When HCl loses H⁺ ion, it forms Cl⁻ which is an acid radical.
 
Following gi...

Asked by Sajjan singh

Nov 24

  • 4 Answers
  • 24 Likes
  • 92533 Views
Syeda answered 1 year(s) , 6 month(s) ago

Different types of clothes in different seasons

Ans:  We are wearing cloths differently in different seasons in order to adjust with the changing atmospheric conditions (suitable for the season).
For example in summer it is suitable...

Asked by Lavanya

Sep 11

  • 47 Answers
  • 44 Likes
  • 90541 Views
Agam answered 1 year(s) , 3 month(s) ago

Explain the life cycle of silk moth?

Ans: Sericulture, or silk farming, is the rearing of silkworms for the production of raw silk.
Life cycle of a silk moth :


1. Egg →2.First stage of larvae→3.Second stage...

Asked by Sneha

Apr 30

  • 3 Answers
  • 16 Likes
  • 81495 Views
Rajan Raman answered 4 year(s) , 1 month(s) ago

Compare the stabilities of O2 , O2-,O22- .

Ans: The stabilities of these can be best explained using Molecular orbital theory.
 
(i)                            Formation Oxygen molecule:
Electronic configuration of oxygen atom-1s...

Asked by Abhiram

Oct 29

  • 3 Answers
  • 3 Likes
  • 65497 Views
Syeda answered 1 year(s) , 5 month(s) ago

Life cycle of silk moth

Ans: Sericulture, or silk farming, is the rearing of silkworms for the production of raw silk.
Life cycle of a silk moth:


1. Egg →2.First stage of larvae→3.Second stage...

Asked by Rohit

Feb 17

  • 4 Answers
  • 16 Likes
  • 62751 Views
Syeda answered 1 year(s) , 6 month(s) ago

Tricks to learn atomic masses first 20 elements

For your grade you need to remember atomic masses of first 20 elements.

The atomic mass is double the atomic number of an element. But it is not applicable for all the elements in the periodic table.

...

Asked by Mragisha

Dec 19

  • 4 Answers
  • 10 Likes
  • 59639 Views
Syeda answered 1 year(s) , 5 month(s) ago

More stable among O2+ and O2-

Answer.

O2+ is more stable than O2-.Because According to molecular orbital theory O2+ has 15 electrons &it has one electron

...

Asked by Prasad

May 19

  • 2 Answers
  • 10 Likes
  • 58919 Views
Syeda answered 1 year(s) , 6 month(s) ago

Evaporation causes cooling.Explain the reason for this effect .Give 2 examples

Evaporation causes cooling because during evaporation the particle of the liqued absord energy from the surroundings to regain the energy lost during evaporation. the absorbtion of heat from the surrounding

...

Asked by Deepak

Sep 1

  • 4 Answers
  • 6 Likes
  • 58371 Views
Syeda answered 1 year(s) , 5 month(s) ago

Why should curd and sour substances not be kept in brass and copper vessels?

curd and sour things have acid in them. so they are sour.
now bras and copper vessels rect well with the food stuffs and the pure food that we keep in it gets reacted with the material of the vessel whi...

Asked by Manikanth

May 17

  • 10 Answers
  • 7 Likes
  • 56525 Views
Syeda answered 1 year(s) , 6 month(s) ago

Difference between solids,liquids and gases

Ans: Property Solids Liquids Gases

  1. Kinetic energy
Very low (negligible) medium Very High
  1. Rigidity
Highly rigid - Posses fixed shape Not rigid- gets the...

Asked by Najiha

Sep 6

  • 6 Answers
  • 7 Likes
  • 56009 Views
Priyanshu answered 1 year(s) , 4 month(s) ago

write the advantages and disadvantages of mendeleev's periodic table and modern periodic table with examples.

Advantage of Mendeleev Periodic Table :-
1.He left blank  Places which help scientist to discover new element
2.When Noble gasses was discovered Hel could add  it to periodic table without any m...

Asked by Ayushman

Feb 26

  • 8 Answers
  • 4 Likes
  • 55878 Views
Syeda answered 1 year(s) , 6 month(s) ago

what is handpicking ? When is this method used?

Handpicking is a method to remove slightly larger impurities like pieces of dirt,stones and husk from wheat,rice and pulses by hand. 

Asked by Sanjeev

Jul 17

  • 3 Answers
  • 4 Likes
  • 55117 Views
Syeda answered 1 year(s) , 6 month(s) ago

What is desirable and undesirable change?

Desirable changes are those that are beneficial[useful].Milk changing into curd,a seed germinating and forming a new plant and bees changing nectar into honey are some examples of desirable change.
Unde...

Asked by Raghavendra

Apr 9

  • 5 Answers
  • 9 Likes
  • 54837 Views
Syeda answered 1 year(s) , 6 month(s) ago

what is rancidity ? write different methods of preventing rancidity .

Ans: Rancidity: It is defined as chemical decomposition of oils and fats which in another words is spoiling food materials that difficult for consumption.
It can be prevented by following methods:...

Asked by Nikhil

Jun 13

  • 2 Answers
  • 4 Likes
  • 50766 Views
Syeda answered 1 year(s) , 6 month(s) ago

Difference between Mendeleev's periodic table and modern periodic table

Answer.

Mendeleev's periodic table Modern periodic table Mendeleev's periodic table is based on atomic mass...

Asked by Anuj

Mar 1

  • 3 Answers
  • 7 Likes
  • 42888 Views
Syeda answered 1 year(s) , 6 month(s) ago

How is salt obtained from sea water?

The sea water is first collected and it is kept for evaporation.When the water is fully evaporated the salt remains.By this way salt is obtained from sea water.

Asked by Abhinav

Aug 6

  • 9 Answers
  • 3 Likes
  • 40664 Views
Syeda answered 1 year(s) , 5 month(s) ago

Differences between aliphatic and aromatic compounds

Answer.

Property Aliphatic compounds Aromatic compounds Structure In aliphatic compounds the Carbon compounds are linked to each other...

Asked by Prasad

May 17

  • 2 Answers
  • 2 Likes
  • 40469 Views
Syeda answered 1 year(s) , 6 month(s) ago

can you explain me why tearing of paper is a physical change and burning of paper a chemical change?

Physical change changes the appearence of the substance but the chemical change will change the actual substances, here tearing of the paper is only changes the appearence of the substance but burning of paper...

Asked by Aena

Oct 21

  • 29 Answers
  • 9 Likes
  • 40364 Views
Agam answered 1 year(s) , 4 month(s) ago

Given a chemical test to distinguish between (i) Ethane and ethene (ii) Ethanol and ethanoic acid (iii) Soaps and Detergents

Ans: ( i) Ethane and ethene:
Then,  addition of bromine water to both alkane and alkene. In which ever case colour changes that compound is ethene (alkene).
E...

Asked by Narasimha

Oct 7

  • 2 Answers
  • 1 Like
  • 39796 Views
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