// //]]>
##### 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

### 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) , 5 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...

Dec 17

• 31 Likes
• 140062 Views

Dec 17

Vikas answered 4 year(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

• 28 Likes
• 109745 Views

Asked by Sajjan singh

Nov 24

Syeda answered 1 year(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.

...

Dec 19

• 10 Likes
• 68490 Views

Dec 19

Swathi answered 4 year(s) , 5 month(s) ago

All the important formulae relating with mole concept

HERE YOU SHOULD KNOW A FEW SYMBOLS.
n = no. of moles
N = no. of particles ( atoms, molecules, ions)
N 0 = avogadro constant ( 6.022 * 10 23)
m = mass...

Dec 15

• 3 Likes
• 30847 Views

Dec 15

Satyanarayana answered 4 year(s) , 4 month(s) ago

If one mole of carbon atom weighs 12g,what is the mass in grams of 1 atom of carbon

Mass of one mole of carbon atom = 12g

1 mole of a carbon contains 6.022 X 1023 atoms

Hence, mass of 6.022 X 1023 Atoms of carbon = 12g

Mass of 1 atom of carbon

...

Feb 5

• 5 Likes
• 28631 Views

Feb 5

Saloni answered 2 year(s) , 3 month(s) ago

uses of ISOBARS

Isobars of uranium were used in nuclear reactor.
Isobars of cobalt were used in treatment of cancer.
Isobar of iodine was used in treatment of goitre.

Oct 16

• 3 Likes
• 21766 Views

Oct 16

Swathi answered 4 year(s) , 6 month(s) ago

How many oxygen atoms are present in 88 g of Carbon dioxide

Molar mass of CO2 = 44g/mol

Number of moles of CO2 present in 88g  of CO2 =  88g/44g mol-1

= 2 moles

1 mole of CO2 contains 2

...

Nov 23

• 1 Like
• 20825 Views

Nov 23

Swathi answered 4 year(s) , 3 month(s) ago

Calcium Carbonate (CaCO3) contains 40% calcium , 12% carbon and 48 % oxygen by mass.calculate the mass of the constituent elements in 2g of calcium carbonate

According to law of definite proportions, in a chemical substance, the elements are always present in definite proportions by mass.
Given data:
Percentage of Ca present in CaCO3 – 40%<

...

Feb 20

• 1 Like
• 15084 Views

Feb 20

Prasoon Kumar answered 4 year(s) , 5 month(s) ago

what is the difference between 2N and N2

2N represents two atoms of nitrogen whereas N 2 represents one molecule of nitrogen gas.

Nov 16

• 1 Like
• 15010 Views

Nov 16

Sahal answered 3 year(s) , 2 month(s) ago

nitrogen and hydrogen combine in the ratio 14 : 3 by mass to form ammonia molecule . find the formula by calculating the molar ratio (given mass N = 14u , H = 1) u

Substance makes cell wall in fungi

Asked by Syed ismial

Mar 16

• 1 Like
• 14239 Views

Asked by Syed ismial

Mar 16

Satyanarayana answered 4 year(s) , 2 month(s) ago

Why metals are electropositive and non-metals are electronegative in nature?

metals have less than 4 electrons in their valence shell . hence its easier 2 give 1,2,3 electrons than 2 receive 5,6,7 electrons to complete d octet configuration.   eg. in Na no of electrons is 11 so valence...

Mar 21

• 1 Like
• 13511 Views

Mar 21

Satyanarayana commented 5 year(s) , 5 month(s) ago

How many atoms are there in exactly 12g of carbon?

Ans:  Yes, it is possible to calculate the number of atoms present in 12 grams of carbon. For this it requires to find the number of moles of given substance.
Number of moles = given weight/ atomic weig...

Jan 6

• 2 Likes
• 12480 Views

Jan 6

Swathi answered 4 year(s) , 1 month(s) ago

How many moles of electron weighs 1 kg

Mass of electron = 9.1 x 10-31Kg

One mole of electrons = 6.023x1023

Mass of 1 mole of electrons = 6.023x1023 x 9.1 x 10-31Kg

How many moles

...

Apr 23

• 1 Like
• 11317 Views

Apr 23

Adithyan answered 4 year(s) , 2 month(s) ago

Symbols and names of elements derived from latin name

Name                           Latin Name                          Symbol

Potassium                    Kalium                                K
Soduim                        Natrium      ...

Feb 3

• 1 Like
• 10988 Views

Feb 3

Swathi answered 4 year(s) , 6 month(s) ago

How many atoms of oxygen are present in 3oo grams of calcium carbonate

Molecular mass of calcium carbonate = 40 + 12 + 48 =100g

1 mole of Calcium carbonate contains – 3 mole of oxygen atoms

100 g of Calcium carbonate contains - 3 X 6.022 X 1023 oxyge

...

Asked by Dr s saravanan

Dec 13

• 0 Like
• 10920 Views

Asked by Dr s saravanan

Dec 13

Swathi answered 4 year(s) , 5 month(s) ago

How to find number of valence electrons using ionization energy?

Ans:

Ionization Energy is the minimum energy required to remove the outermost electron from a gaseous neutral atom to form a cation.
The unit for ionization energy is electron volts or kilo jo

...

Jan 5

• 0 Like
• 9721 Views

Jan 5

Swathi answered 4 year(s) , 5 month(s) ago

What are the valencies of cuprous and cupric and ferrous and ferric

Some elements like copper and iron exhibits more than one valency. That is they have variable valencies.

Generally the name of the element end in 'ous' for lower valency and end in 'ic' for higher va

...

Dec 21

• 0 Like
• 9601 Views

Dec 21

Satyanarayana answered 4 year(s) , 5 month(s) ago

Atomic masses of some important elements That are Important of us.A chart of atomic masses

Ans: Following table gives the atomic mass of first 20 elements of the periodic table. These atomic masses are more useful for you.

Atomic number Symbol Element Name Atomic mass 1 H Hydrogen 1 2 H...

Dec 15

• 1 Like
• 9227 Views

Dec 15

Satyanarayana answered 4 year(s) , 1 month(s) ago

A compound has the molecular formula X4O6 if 10 g of X4O6 has 5.72 g of X, then Find atomic mass of X?

Ans:
Molecular formula of the compound =  X 4 O 6
10 grams of X 4 O 6  contains 5.72 grams of X.
Percentage of X in given molecule = (5.72...

Apr 16

• 1 Like
• 7993 Views

Apr 16

Swathi answered 4 year(s) , 2 month(s) ago

How to find valency of K2Cr2O7?

The combining capacity of an element is called its valency.
or
The number of electrons lost, gained or shared by an atom of an element during chemical reaction for attaining stable electronic con...

Apr 8

• 0 Like
• 7721 Views

Apr 8

###### 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