CBSE Questions for Class 9 Chemistry Atoms And Molecules Quiz 1 - MCQExams.com

Who called the indivisible particles as atoms?
  • Antoine L. Lavoisier
  • Democritus
  • Rutherford
  • Both B and C
________ is the latin name for sodium.
  • Sodiumin
  • Natrium
  • Natrimium
  • Kalium
When did Maharishi Kanad give the idea of parmanu ?
  • $$ 500 BC $$
  • $$ 100 BC $$
  • $$ 460 BC $$
  • $$ 1808 BC $$
What is atomic mass of $$He$$ in amu $$(u)$$ units?
  • $$8$$
  • $$9$$
  • $$2$$
  • $$4$$
The cation in $$CaCl_2$$ is:
  • $$Ca^{+}$$
  • $$Cl^{2-}$$
  • $$Ca^{2+}$$
  • $$Cl^{2+}$$
The term mole is a latin word which means:
  • bunch
  • heap or pile
  • herd
  • flock
Avogadro number is equal to:
  • $$6.023\times10^{21}$$
  • $$6.023\times10^{22}$$
  • $$6.023\times10^{23}$$
  • $$6.023\times10^{24}$$
One mole is defined as:
  • quantity having a mass equal to its atomic/molecular mass.
  • quantity having mass equal to half of its atomic/molecular mass.
  • one gram of any quantity.
  • one kilogram of any quantity.
Which of the following property of an element never changes?
  • Valency
  • Atomic weight
  • Both A and B
  • None of the above
Cation and anion present (if any) in NaCl is :
  • Anion: $$Cl^{2-}$$ Cation: $$Na^+$$
  • Anion: $$Cl^{-}$$ Cation: $$Na^{2+}$$
  • Cation: $$Cl^{-}$$ Anion: $$Na^+$$
  • Anion: $$Cl^{-}$$ Cation: $$Na^+$$
Avogadro's number is the number of molecules present in:
  • 1 g of molecule
  • 1 atom of molecule
  • 1 mole
  • 1 litre of molecule
Calculate the molecular mass of the lime stone.
  • $$CaCO_2 = 84 g mol^{-1}$$
  • $$CaCO_3 = 100 g mol^{-1}$$
  • $$Ca_2CO_3 = 140 g mol^{-1}$$
  • $$CaCO = 68 g mol^{-1}$$
Cations and anions present (if any) in $$H_2$$ are:
  • $$H^+$$
  • $$H^-$$
  • $$H^{2+}$$
  • None of the above
The value of 1 amu is equal to:
  • $$1.66\times 10^{-8}g$$
  • $$1.66\times 10^{-4}g$$
  • $$1.66\times 10^{-16}g$$
  • $$1.66\times 10^{-24}g$$
The formula and molecular mass of caustic soda is :
  • $$NaOH = 40 g mol^{-1}$$
  • $$Na_2OH = 63 g mol^{-1}$$
  • $$Na(OH)_2 = 57 g mol^{-1}$$
  • none of the above
Calculate the molecular mass of the baking powder.
  • $$NaHCO_2 = 68 g mol^{1}$$
  • $$Na_2HCO_3 = 107 g mol^{1}$$
  • $$NaHCO_3 = 84 g mol^{1}$$
  • none of these
The % of Copper and Oxygen in samples of CuO obtained by different methods were found to be the same. 
This proves the law of:
  • constant proportions
  • reciprocal proportions
  • multiple proportions
  • conservation of mass.
Which of the following is used as standard for determination of atomic mass unit?
  • $$O^{16}$$
  • $$C^{12}$$
  • $$H^{1}$$
  • $$O^{17}$$
A negatively charged ion is known as anion.
  • True
  • False
Which one of the following properties of an element is not variable?
  • Valency
  • Atomic weight
  • Equivalent weight
  • All of these
The element lead is derived from the Latin name plumbum.
  • True
  • False
The symbols of lead and mercury are respectively:
  • $$Hg, Pb$$
  • $$Pb, Hg$$
  • $$Le,Me$$
  • $$Ld, My$$
A molecule is made up of like atoms.
  • True
  • False
A symbol of an element is always represented by the first alphabet of an atom of the element.
  • True
  • False
A balanced chemical equation is in accordance with the law of conservation of mass.
  • True
  • False
Number of atoms in $$12$$ gm of  $$^{12}_6C$$ is:
  • $$6$$
  • $$12$$
  • $$6.02\times 10^{23}$$
  • $$6\times 6.02\times 10^{23}$$
The value of the Avogadro constant is :
  • $$6.022\times 10^{24}$$
  • $$6.022\times 10^{22}$$
  • $$60.22\times 10^{24}$$
  • $$6.022\times 10^{23}$$
Mass of one twelth of carbon atom is called atomic mass unit.
  • True
  • False
_________ is the smallest unit of matter which may or may not have an independent existence, but always takes part in a chemical reaction.
  • An Atom
  • A compound
  • A crystal
  • All the above
Molecular weight of water is $$20$$ u.
  • True
  • False
The molecular mass of $$(NH_2)_2CO$$ is :
(Given atomic mass of H = 1, O = 16, C = 12, N = 14.)
  • $$90gm/mole$$
  • $$80gm/mole$$
  • $$60gm/mole$$
  • $$62gm/mole$$
A symbol of an element does not convey information about:
  • Atomic number
  • Atomic weight
  • Mass number
  • All of the above
An atom is different from its ion in:
  • nuclear charge
  • mass number
  • number of electrons
  • number of neutrons
The molecular mass of $$Mg_3N_2$$ is ::
Given atomic mass of $$(N = 14, Mg = 24.)$$
  • $$84gm/mole$$
  • $$98gm/mole$$
  • $$114gm/mole$$
  • $$100gm/mole$$
What is the representation of atom of hydrogen and a molecule of hydrogen?
  • $$H$$ and $$H_2$$
  • $$H_2$$  and  $$H$$
  • $$H$$  and  $$H$$
  • $$H_2$$ and $$H_2$$
The statement "atom is indivisible" was proposed by:
  • Rutherford
  • Dalton
  • Bohr
  • Einstein
The chemical formula of a particular compound represents:
  • the size of molecule
  • the shape of its molecules
  • the total number of molecules in the compound
  • the number of different types of atoms in its molecule
Which is the smallest possible unit of a chemical compound?
  • Atom
  • Electron
  • Proton
  • Molecule
Law of constant composition is also called as the law of :
  • Conservation of mass
  • Conservation of energy
  • Multiple proportion
  • Definite proportion
A 'mole' of a substance is the same as ________.
  • avogadro's number of particles of the substance
  • the molecule
  • the quantity of substance reacting with 8 parts of oxygen
  • the saturated solution of the substance
The amount of a chemical substance is reported as _______.
  • mole
  • mass
  • volume
  • density
Which is the lightest element in the universe?
  • Helium
  • Hydrogen
  • Nitrogen
  • Silicon
Which of the following represents Plumbous ion?
  • $$Pb^{+2}$$
  • $$Pb^{+4}$$
  • $$Pb^{+3}$$
  • $$Pb^{+1}$$
The atomic theory of matter was proposed by :
  • John Kennedy
  • Lavoisier
  • Proust
  • John Dalton
Avogadro's number represents the number of atoms in:
  • 12 g of $$C^{12}$$
  • 320 g of sulphur
  • 32 g of oxygen
  • 14.3 of sulphur
The smallest unit of a compound is called a molecule.
  • True
  • False
The mass number of sulfur atom is:

(Given: Atomic number = 16 and number of neutrons = 16)
  • 18
  • 32
  • 24
  • 16
Mass of atom expressed in atomic mass unit is :
  • Atomic mass
  • Molecular mass
  • Atomic number 
  • None of the above
What is the atomic mass (u) of calcium?
  • 10
  • 20
  • 30
  • 40
One a.m.u is defined as mass of  :
  • $$\frac{1}{16}^{th}$$ mass of one oxygen atom
  • $$\frac{1}{14}^{th}$$ mass of one atom of nitrogen
  • $$\frac{1}{12}^{th}$$ mass of one carbon-12 atom
  • None of above
0:0:1


Answered Not Answered Not Visited Correct : 0 Incorrect : 0

Practice Class 9 Chemistry Quiz Questions and Answers