write 5-6 differences between isobars and isotopes in a tabular form .

• 1.  a/2
• 2.  a
• 3.  a/(4/√3)
• 4.  a/(4/√2)

how to find valency of an element?

what were the drawbacks of thomson model of atom

what is the difference between sodium ion and sodium atom ?

Calculate the number of molecules in 8g of Oxygen ?

find the valency of sulphur .[atomic no.=16

• 1.  (100)
• 2.  (110)
• 3.  (111)
• 4.  None

what are canal rays ?

5 examples of isotopes and 5 examples of isobars

 What is the valency of copper?

EXPLAIN THE LAW OF CONSERVATION OF MASS WITH AN EXAMPLE ?

Compare the properties of electrons, protons and neutrons.

what are the application of isotopes

what is the atomicity of ammonia

What are the drawbacks of Rutherfords atomic model?

What is the maximum number of energy levels in an atom?

Q.1. How many molecules are present in

(a) 9 grams of water

(b) 17 grams of amonia

Q.2. Calculate the number of moles in 17 grams of H₂O₂

Q.3. Show that 12 grams of carbon-12 contains 6.023 x 10²³ atoms of ¹²C

Q.4. What is the mass of one atom of hydrogen ?

Q.5. How many moles of Mg atoms are there in 100 grams of magnesium ?

Q.6. Neon gas consist of single atoms. What mass of neon contains 6.023 x 10²³ atoms ?

• 1.  Projected area fraction of atoms on a plane
• 2.  Distance between two adjacent atoms
• 3.  Volume fraction of atoms in cell
• 4.  None

difference between electrons protons and neutrons...also find the relation between the three

• 1.  Vacancy- interstitial pair of cations
• 2.  Interstitial impurity
• 3.  Substitutional impurity
• 4.  Pair of nearby cation and anion vacancies

 Who discovered proton? Golstein or Rutherford?

The charge/mass ratio of electron

a) depends upon nature of gas

b) depends upon nature of electrodes

c) remains constant

d) depends upon both nature of gas and nature of electrodes

1. define mole
2. how is it related to avogadro constant , relative mass and molecular mass
3. what is the no. of molecules in 0.25 moles of oxygen . avogadro's no =6.022*10 power is 23

Q1 Tabulate name of elements,their latin names and symbols.

explain the rutherford's gold foil experiment with the help of diagram?

what is electrovalency and covalency

Suppose that there were two natural isotopes of Copper. 80% of the atoms had a mass of 63, and 20% of the atoms had a mass of 65. What would that average atomic weight of copper be?

(a) What are isobars? Give one example. (b) Write any two uses of isotopes

Write two differences between isobars and isotopes.

 Which subatomic particle was not present in thomson mode of the atom

why is the valency of phosphorus 3 & 5 both ?

Suppose that there were two isotopes of Sodium. 28% of the naturally occurring sodium atoms had a mass of 22, and 72% atoms had a mass of 23. What would the average atomic weight of sodium be?

How to learn the 30 elements of modern periodic table Quickly?

Calculate the no. of atoms of each element persent in 9.8 g of sulphuric acid, H₂SO₄. (H=1, S=32, O=16)

what r the rules of distribution of electrons in different shells of an atom.Pls give me all rules of higher classes also.

• 1.  <uvw>
• 2.  (hkl)
• 3.  {hkl}
• 4.  [uvw]

What is the valency of Aluminium whose atomic number is 13 ? Give reason.

what is the valency of gold, silver and lead and can you explai how we can find the valency of a compound like NH₄, SO₂, CO₃ etc.

discrete orbits are also known as_____

what are properties of anode rays x rays cathode rays and alpha particles

 wht r d drawbacks of bohr's model of an atom??

 Give 6 examples of isobars .........

valency of carbon in CH4 , C2H6 , C2H4 , C2H2 ???

 discovery of electrons

Calculate the percentage of

[a] Water of crystallization in CuSO4.5H2O

[B] Potassium in K2CO3

[c] Oxygen in 22g of CO2

[D] Hydrogen in 36g of water

what are sub shells ?? Who discovered them and how ??? the discoverer of sub shells disproved which scientist

State 3 characteristics of canal rays.

​Calculate number of neutrons present in 12 × 10²⁵ atoms of oxygen (₈O¹⁷). (Given N_A = 6 × 10²³ atoms)

(A) 1800 (B) 1600 (C) 1800 N_A (D) 3200 N_A

 State two main postulates of Thomson model of an atom

 applications and examples of isotopes an isobars ?

difference between protons and anode rays

and electrons and cathode rays

the description of atomic particles of two elements X and Y is given below:

X Y

protons 8 8

neutrons 8 9

electrons 8 8

i) what is the atomic number of Y?

ii) what is the mass number of X?

iii) what is the relation between X and Y?

iv) which element/elements do they represent?

v) write the electronic configuration of X.

vi) write the cation/anion formed by the element.

What does indivisible mean in terms of chemistry?

1. Calculate the molecular mass of CaCO₃ at mass Ca=40u,C=12u,O=16u
2. Verify by calculating that

• 5 moles of CO₂ and 5 moles of H₂O do have the same mass.
• 240g of calcium and 240g of magnisium element have a mole ratio of 5:3.at mass H=1u ,Ca=40u,Mg=24u

Calcualte the effective nuclear charge ( Z^*) of Na⁺.

p.s. Don't know to which class this question would belong to!:P I'm reading it in IIT coaching!

what is difference between Isotopes, Isobars and Isotones

An ion (M²⁺) contain 10 electrons and 12 neutrons what is the atomic number and mass number of the element M.

give the atomic masses of important element for class 9

an element X forms an oxide with formula X₂O₃

state the valency of X,write the formula of chloride of X and sulphate of X.

difference between isotope and isobars

identify the isotopes out of A,B,C and D?

³³A₁₇ , ⁴⁰B₂₀ , ³⁷C₁₇ , ³⁸D₁₉

The electronic configuration of potassium(K) is 2,8,8,1 instead of 2,8,9 thogh the M shell can accommodate up to 18 electrons. Explain

What is the atomic mass and atomicity of Potassium ?

who discovered the proton? E. goldstein or rutherford?

If Z = 3, what would be the valency of the element? Also, name the element.

write three significant features of Bohr's model of an atom.

Name three feature of rutherford's model

how to draw Na+ ion??????????