Structure Of The Atom, Popular Questions: Karnataka Class 9 SCIENCE, Science

Abhishek Malhotra asked a question

Subject: Science, asked on on 11/2/13

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

Tejas Sankhwar asked a question

Subject: Science, asked on on 21/1/18

How to rememeber the no. of neutrons of 1 to 20 elements

Saarah Huda asked a question

Subject: Science, asked on on 16/1/12

how to find valency of an element?

Ruchit.chudasama asked a question

Subject: Science, asked on on 26/10/16

The atomic diameter of an BCC crystal (if a is lattice parameter) is

1. a/2
2. a
3. a/(4/√3)
4. a/(4/√2)

Saket Jha asked a question

Subject: Science, asked on on 12/1/13

what were the drawbacks of thomson model of atom

Anshumaan Singh asked a question

Subject: Science, asked on on 21/1/13

which has highest e/m ratio

a) he 2+

b)h

C)H+

d) he+

Yadhukrishna asked a question

Subject: Science, asked on on 21/2/13

Calculate the number of molecules in 8g of Oxygen ?

Keshav Singh 😎👑👻😎 asked a question

Subject: Science, asked on on 12/11/18

write the advantage and disadvantage of thomson model of atom

Lisby Saji & 1 other asked a question

Subject: Science, asked on on 29/9/14

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

P D asked a question

Subject: Science, asked on on 3/4/15

BF3 + Li2SO3--------->B2(SO3)3 + LiF
BALANCE THIS EQUATION

Alisha Saluja & 1 other asked a question

Subject: Science, asked on on 27/1/13

what are canal rays ?

Ruchit.chudasama asked a question

Subject: Science, asked on on 26/10/16

Miller indices for Octahedral plane in cubic crystal

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

Hari Krishnan asked a question

Subject: Science, asked on on 8/3/13

5 examples of isotopes and 5 examples of isobars

Vidit Goyal asked a question

Subject: Science, asked on on 31/12/12

1.An element ‘X’ forms an oxide with formula X2O3. State the valency of ‘X’ and write the formula of its

chloride

2. Define mole. How many grams of sodium will have the same number of atoms as 6 grams of

magnesium ? (Given Na5 23u, Mg5 24 u)

3. You are given an elements . Find out (a) Number of protons, electrons and neutrons in ‘X’ (b) Valency of

‘X’ (c) Write the chemical formula of the compound formed when ‘X’ react with (i) hydrogen, (ii) carbon

168X

4. An elements has mass number 35 and atomic number 17 find (i) the number of neutron in the element,

and (ii) the number of electrons in the outermost shell.

5. Name the anion and cation which constitute the molecule of magnesium oxide

6. Percentage of three elements calcium, carbon and oxygen in a sample of calcium carbonate is given as :

Calcium =40% ; Carbon =12.0% ; Oxygen = 48%

If the law of constant proportion is true, what weights of these elements will be present in 1.5 g of another

sample of calcium. Carbonate ?

(Atomic mass of Ca = 40 u, C = 12 u, O = 16 u)

7. The description of atomic particles of two elements X and Y is given below :

(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

8. Which of the following are isotopes and which are isobars?

Argon, Protium, Calcium, Deuterium. Explain why the isotopes have similar chemical properties but they

differ in physical properties?

9.What is the number of molecules in 0.25 moles of oxygen ? Avogadro’s no. 6.02×10

23

.

10. Write down the formulae of

(a) sodium carbonate (b) Ammonium chloride (c) Zinc oxide (d) Aluminium hydroxide11.What do the following symbols formulae stand for : (a) 2O (b) O2 (c) O3 (d) H2O (ii) Give the chemical

formulae of the following compounds : (a) Potassium Carbonate (b) Calcium chloride (iii) Calculate the

formulae unit mass of Al2 (SO4)3 (Given atomic mass of Al – 27u, S – 32u, O – 16u)

12. Write the chemical formula of ammonium sulphate.

13. The composition of nuclei of two atomic species X and Y are given below

X Y

Protons 17 17

Neutrons 18 20

Find the mass number of X and Y. State the relationship between X and Y

14. Find the mass of the following : (i) 0.5 mole of oxygen gas (ii) 3.011×10

23

atoms of oxygen (iii) 6.022×10

24

molecules of oxygen (Given atomic mass of 0=16u; No. of molecule=6.022×10

has completely filled K,L and M shells. Find its atomic number.

16. Find the number of particles in each of the following : (i) 0.1 mole of C atoms (ii) 46 g of Na atoms

(Given that Na = 23u ; No. of molecule=6.022×10

23

per mole

17. Calculate the number of moles present in (i) 60g of calcium (ii) 3.011×10

23

number of oxygen atoms

(Given that Ca = 40u ; Avogadro number= 6.022×10

23

)

18. State one use each of an isotope of (i) uranium , (ii) iodine.

19. The chemical formula of oxide of an element X is X2O5. Write the chemical formula of its chloride.

20. Calculate the number of particles in each of the following : (i) 7 g of Nitrogen molecules (ii) 0.5 mole of

carbon atoms (Given N=14 u ; C=12 u ; Avogadro number= 6.022×10

23

)

21. Which of the following compounds have polyatomic ions ? NaOH, NaCl, Na2O, NaNO3

22. Sulphur dioxide (SO2) is a colourless pungent smelling gas and is a major air pollutant. (a) Write the

electronic configuration of its constituent elements „sulphur and Oxygen. (Given, ). (b) Write valency of

Sulphur and Oxygen. (c) Are sulphur and oxygen isotopes of same element. Explain your answer. (Given

32

S16 ,

16O8)

23. What is the mass of 0.5 mole of NH3 ? Given Atomic mass of N = 14u, Atomic mass of H = 1u. (c)

Calculate the number of particles in 31 g of P4molecules. Atomic mass of P=31u. ( Avogadro number=

6.022×10

23

) (d) Find the number of moles in 87g of K2SO4 (Atomic mass of K=39u, S=32u

24. A light and a heavy object have the same momentum. What is the ratio of their kinetic energies ? Which

one has a larger kinetic energy ?

(ii) A ball is dropped from a height of 10m. If the energy of the ball reduces by 40% after striking the

ground, how much high can the ball bounce back ? (g=10 ms

-2

)

25. Write the names of compounds represented by the following formulae : (i) KNO3 (ii) Al2(SO4)3 (iii) CCl4

(iv) H2S

26. Two boys Ram and Shyam have mass equal to 40 kg each. They start climbing a rope separately and

both reach a height of 6 m. Ram takes 20 seconds and Shyam takes 25 seconds to complete the task. Who

has more power? Explain your answer. (Take g =10 m/s

2

)

27. (a) What would be the formula of chloride of ‘X’ if it is a metal and its oxide has the formula XO ? (b)

Write a difference between an atom and an ion. (c) Give an example of each : (i) Triatomic molecule. (ii)

Polyatomic ion. (iii) molecule of a compound (iv) cation (v) an element with valency – 3

28. In an office, a tube light of 40W, a fan of 75 W and a cooler of 150 W are installed. If the appliances are

used for 8 hours per day, find the energy consumed per day in commercial unit.

29. a)Calculate the mass of 0.72 g molecule of CO2. (At mass of C=12 u, O=16 u) (b) Calculate the number of

moles of iron in iron sheet containing 10

22

atoms of iron.

30. Calculate the molar mass of Nitric acid (HNO3). (Atomic Mass of H=1u, N=14u, O=16u) (b) Calculate

the no. of moles in 270 g of Aluminium. (Atomic mass of Al=27 u) (c) Calculate the mass of 0.5 moles of

Helium gas (Atomic mass He=4u.)

Nikhita Dharmavaram asked a question

Subject: Science, asked on on 26/11/11

What is the valency of copper?

Saitama asked a question

Subject: Science, asked on on 23/1/15

Important formulas for chapter of chemistry foundation 1 of class 9 :- (structure of an atom). Also if it is in revision notes please tell me where it is.

Nupur Thakur & 1 other asked a question

Subject: Science, asked on on 11/10/13

EXPLAIN THE LAW OF CONSERVATION OF MASS WITH AN EXAMPLE ?

Jilsa asked a question

Subject: Science, asked on on 31/3/15

Classify the following compounds as diatomic,triatomic and polyatomic molecules.
HCl,
H₂,
H₂O,
NH_3,
CH₃OH,
PCl₅

Gagan Malik asked a question

Subject: Science, asked on on 13/6/10

Compare the properties of electrons, protons and neutrons.

Abdul S Mapara asked a question

Subject: Science, asked on on 23/2/13

force on electron F=eE what e and E stands for.

Dalen & 6 others asked a question

Subject: Science, asked on on 3/7/15

what are the application of isotopes

Ananya Aggarwal asked a question

Subject: Science, asked on on 12/11/14

The nucleon number of atom X is 37. It exists as a diatomic molecule, X2. One molecule of X2 contains 34 protons. How many neutrons are present in the nucleus of atom X?

Aqeel Abdul Rahman asked a question

Subject: Science, asked on on 9/3/13

What are the drawbacks of Rutherfords atomic model?

Aditya Ravi asked a question

Subject: Science, asked on on 21/12/14

If a 0.9% solution is isotonic to a certain type of animal cell, the cell will lose mass if it is placed in
which of the following liquids?
(1) 0.5% salt solution (2) 0.9% salt solution
(3) 1.2% salt solution (4) distilled (pure) water

Aman Kumawat asked a question

Subject: Science, asked on on 7/1/12

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 ?

Rohan Asrani asked a question

Subject: Science, asked on on 9/1/12

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

Alisha Saluja asked a question

Subject: Science, asked on on 22/2/13

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

Fayaaz Mohammed asked a question

Subject: Science, asked on on 7/12/14

What is the difference between perforated cathode and normal cathode?Why can't we use normal cathode in Thomson's Atomic Model to find anode rays?

Vrinda Ojha asked a question

Subject: Science, asked on on 19/11/12

Who discovered proton? Golstein or Rutherford?

Yash Asher asked a question

Subject: Science, asked on on 23/2/12

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

Siddhanth Ravichandran asked a question

Subject: Science, asked on on 17/2/12

an ion M³⁺ contains 10 electrons and 14 neutrons.What are the atomic mass and mass number of the element M ? name the element

Anjali Thakur asked a question

Subject: Science, asked on on 17/5/12

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

Kingshuk Dutta asked a question

Subject: Science, asked on on 19/1/16

alpha particles are doubly charged helium ions. Since they are much more heavier than electrons, they would not get deflected upon collision with electrons. We get to know that most of the space inside the electrons is either empty or comprises of electrons.....but how can we directly conclude that the space inside an atom is empty through the alpha particle experiment? It can also be that its is not empty and comprises of electrons.......

Pooja Ravikumar asked a question

Subject: Science, asked on on 5/3/13

what is the difference between sodium ion and sodium atom ?

Mrinal Patwari asked a question

Subject: Science, asked on on 9/3/14

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

Shivangi Bhardwaj asked a question

Subject: Science, asked on on 18/2/15

If X- contains 18 electrons, what is its atomic number?

Harshita Sharma asked a question

Subject: Science, asked on on 25/2/12

what is electrovalency and covalency

Michio Kaku & 1 other asked a question

Subject: Science, asked on on 4/5/13

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

Write two differences between isobars and isotopes.

Punarv Gangnaik asked a question

Subject: Science, asked on on 10/11/13

Calculate the molecular mass of CaCO₃ at mass Ca=40u,C=12u,O=16u
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

Vipin Beniwal asked a question

Subject: Science, asked on on 20/11/14

Ions are more stable than atoms , Give reason ?

Greeshma asked a question

Subject: Science, asked on on 16/10/12

What does indivisible mean in terms of chemistry?

Siddharth Yadav asked a question

Subject: Science, asked on on 3/3/12

why is the valency of phosphorus 3 & 5 both ?

Alvin Jacob asked a question

Subject: Science, asked on on 12/11/13

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

Abhinav Kale asked a question

Subject: Science, asked on on 18/2/13

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

Vishal asked a question

Subject: Science, asked on on 25/2/13

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

Pragyan Priyadarsini asked a question

Subject: Science, asked on on 8/3/15

An element ₁₂X²⁴ loses two electrons to form a cationwhich combines with the anion of element ₁₇Y³⁵ formed by gaining an electron.
1) write the electronic configuration of element X
2)write the electronic configuration of anion of element Y
3) write the formula of the compound formed by the combination of X and Y.

Yatri Sheth & 1 other asked a question

Subject: Science, asked on on 9/10/14

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

Shayoni Guha asked a question

Subject: Science, asked on on 28/2/16

An atom of an element has 7 electrons in its L shell:
a) What is its atomic no.?
b) State its valency
c) Identify the element.

Dharani Dharan & 1 other asked a question

Subject: Science, asked on on 7/6/13

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, CO₃etc.

Sagar asked a question

Subject: Science, asked on on 18/10/12

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

P D asked a question

Subject: Science, asked on on 3/4/15

B2Br6 + HNO3--------> B(NO3)3 + HBr

Simran Singh asked a question

Subject: Science, asked on on 10/3/11

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

Deepesh Sonkar asked a question

Subject: Science, asked on on 2/8/20

How much elements to learn in periodic table with tricks in class 9

Peri & 3 others asked a question

Subject: Science, asked on on 23/2/15

Give 6 examples of isobars .........

Smrithy Balakrishnan asked a question

Subject: Science, asked on on 7/2/13

How many atoms are present in SO4 raised to 2- ion and NH4+ ion???

Yash Dev Lamba asked a question

Subject: Science, asked on on 21/1/13

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

Hemasri Rajendiran asked a question

Subject: Science, asked on on 8/2/14

discrete orbits are also known as_____

jaybhartigupta... asked a question

Subject: Science, asked on on 13/1/11

discovery of electrons

Ruchit.chudasama asked a question

Subject: Science, asked on on 26/10/16

Atomic packing factor is

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

ANIRUDH99 asked a question

Subject: Science, asked on on 19/3/14

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

Ruchit.chudasama asked a question

Subject: Science, asked on on 26/10/16

Schottky-defect in ceramic material is

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

Hardik Sharma & 1 other asked a question

Subject: Science, asked on on 29/1/14

State 3 characteristics of canal rays.

Anurag Pandey asked a question

Subject: Science, asked on on 9/2/18

how many electrons protons and neutrons are present in 207Pb82.write its electronic configuration. how many Valence Electrons does it have ?what will be its valency?

Aditya Sangani asked a question

Subject: Science, asked on on 26/3/16

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

Abhishek Malhotra asked a question

Subject: Science, asked on on 17/2/13

what is the valency of silicon ? is it positive or negative ? is it a metal or non-metal or a metalloid ?

Aagam Shah asked a question

Subject: Science, asked on on 1/2/13

State two main postulates of Thomson model of an atom

Rishi Ahuja asked a question

Subject: Science, asked on on 27/2/13

State 2 point difference between nucleons and nucleus

Shubham Sharma asked a question

Subject: Science, asked on on 4/3/13

applications and examples of isotopes an isobars ?

Google Me asked a question

Subject: Science, asked on on 9/11/13

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!

Shakshi Gupta asked a question

Subject: Science, asked on on 18/12/13

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.

Suroj Dey asked a question

Subject: Science, asked on on 16/7/14

Why do like charges repel and how does unlike charges attract each other

Isha Jindal asked a question

Subject: Science, asked on on 28/2/18

Please ans question 18

18. a) Illustrate the postulates of Neil Bohr to explain the model of an atom.
b) Identify the element, write electronic configuration and number of neutrons present in the atom represented by

{}_{13}X^{27}

OR

a) Illustrate observations and conclusion drawn by Rutherford after conducting Gold foil experiment with the help of diagram.
b) Atomic number of an element is 17 . Identify the element and mention Its valency.

Angel Anjali asked a question

Subject: Science, asked on on 12/2/12

what is difference between Isotopes, Isobars and Isotones

Kavyansh Saxena asked a question

Subject: Science, asked on on 5/3/20

I want the solution of my one plz plz plz

Sandeep Prasad & 2 others asked a question

Subject: Science, asked on on 27/2/15

give the atomic masses of important element for class 9

G asked a question

Subject: Science, asked on on 26/2/16

WHAT IS THE DIFFERENCE BETWEEN ATOMICITY AND AND ATOMIC NUMBER???

Asra Khan asked a question

Subject: Science, asked on on 2/3/13

an element X forms an oxide with formula X₂O₃

rn

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

Mathew Jacob asked a question

Subject: Science, asked on on 3/4/16

On the basis of the protons, neutrons and electrons in the samples given below find: SAMPLE PROTONS NEUTRONS ELECTRONS A 19 20 16 B 18 19 18 C 17 20 17 D 17 17 17
a) the cation
b) the pair of isobars and
c) the pair of isotopes
Also give reason in each case.

Pkborghate asked a question

Subject: Science, asked on on 31/12/11

difference between isotope and isobars

Jasvir Singh Sandhu asked a question

Subject: Science, asked on on 22/2/20

Assertion: Nucleus of an atom is positively charged.
Reason: Nucleus of an atom consists of Protons and Neutrons.

*What is the answer?*

a) Both A and R is true and R is the correct explanation of A.
b) Both A and R is true but R is not the correct explanation of A.
c) A is true but R is false.
d) Both A and R are false.

Stebin asked a question

Subject: Science, asked on on 17/3/14

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

Yatharth.Suri asked a question

Subject: Science, asked on on 2/1/12

mam please explain what problem of atomic structure was solved by discoof nutron

Abhishek Pal & 1 other asked a question

Subject: Science, asked on on 10/1/14

who discovered the proton? E. goldstein or rutherford?

Karanpreet Singh asked a question

Subject: Science, asked on on 2/3/12

According to bohr's model of an atom, electron revolves around the nucleus in the fixed orbits called stationary states or energy shells. Electron does not emit nor absorb energy when it revolves. WHY IS IT SO?

Bohr argued that Rutherford's model would be highly unstable because according to him (bohr) if an electron revolves continously it would be subjected to accelaration. Thus, electron will continously emit radiation and fall in the nucleus. But when electron revolves around the nucleus in Bohr's model it also changes its energy shells, then why the bohr's model is not unstable?

Akrity Khetan asked a question

Subject: Science, asked on on 4/7/10

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