// //]]>
Get a free home demo of LearnNext

Available for CBSE, ICSE and State Board syllabus.
Call our LearnNext Expert on 1800 419 1234 (tollfree)
OR submit details below for a call back

clear
arrow_back

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.

Can’t find a match Ask?

Swathi answered 4 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
  • 32 Likes
  • 146210 Views
Vikas answered 4 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
  • 28 Likes
  • 111796 Views
Syeda answered 2 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
  • 46 Likes
  • 104828 Views
Rajan Raman answered 5 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
  • 6 Likes
  • 99032 Views
Agam answered 2 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
  • 19 Likes
  • 95014 Views
Syeda answered 2 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
  • 7 Likes
  • 81959 Views
Syeda answered 2 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
  • 12 Likes
  • 78460 Views
Syeda answered 2 year(s) , 5 month(s) ago

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

Answer.

sour substances are cidic in nature,i.e, they have acids in them. So, when they are kept in brass or copper vessels, they react  with them and form poisonous or better to say toxic elemen...

Asked by Manikanth

May 17

  • 10 Answers
  • 8 Likes
  • 72625 Views
Syeda answered 2 year(s) , 6 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
  • 69874 Views
Syeda answered 2 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
  • 69309 Views
Syeda answered 2 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
  • 67854 Views
Priyanshu answered 2 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
  • 66473 Views
Syeda answered 2 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
  • 10 Likes
  • 63672 Views
Agam answered 2 year(s) , 4 month(s) ago

How to blance an equation ? (i) Barium chloride + Aluminium sulphate ------> Barium sulphate + Aluminium chloride

barium chloride + aluminium sulphate --------→ barium sulphate + aluminium chloride
BaCl 2 + Al 2(SO 4) 3  --------→  BaSO + AlCl 3 ...

Asked by Raj

Apr 8

  • 5 Answers
  • 3 Likes
  • 63147 Views
Syeda answered 2 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
  • 62965 Views
Syeda answered 2 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
  • 10 Likes
  • 60579 Views
Syeda answered 2 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
  • 60428 Views
Ravinder answered 5 year(s) , 9 month(s) ago

periodic table 1 to 30 plz give me with atmoic no. mass valency neutron proton and electronic configrution

sir these are given in book i want 21 to 30

Asked by Ravinder

Mar 9

  • 2 Answers
  • 7 Likes
  • 59592 Views
Abhilasha answered 4 year(s) , 9 month(s) ago

write the chemical formula as well as structural formula of soaps and detergents

Soaps are sodium or potassium  salts of long chain  carboxylic acids. The  formula for soap is C₁₇H₃₅COONa, or sodium stearate

Asked by Aditya

Feb 17

  • 2 Answers
  • 1 Like
  • 57762 Views
Syeda answered 2 year(s) , 5 month(s) ago

RELATIONSHIP BETWEEN ∆H &∆U

Relation between ∆H &∆U:
 
Solids and liquids do not show significant change in the volume when heated. Thus if change in volume, ∆V is insignificant
∆H=∆U+P∆V
∆...

Asked by Sagar

Oct 5

  • 2 Answers
  • 8 Likes
  • 55897 Views
Like NextGurukul? Also explore our advanced self-learning solution LearnNext
Offered for classes 6-12, LearnNext is a popular self-learning solution for students who strive for excellence
Explore
Animated Video
lessons
All India
Test Series
Interactive Video
Experiments
Best-in class
books

Join India's most happening

Educational community