Last updated on August 30th, 2023 at 01:44 am
Class 9 Science Atoms and Molecules MCQ
Who was the Indian philosopher who postulated the idea of the smallest particles called Parmanu?
a) Maharishi Kanad
b) Pakudha Katyayama
c) Socrates
d) Plato
Answer: a) Maharishi Kanad
According to Maharishi Kanad, what is the nature of Parmanu?
a) They are invisible particles
b) They are divisible particles
c) They are the smallest particles of matter
d) They are made up of combined forms
Answer: c) They are the smallest particles of matter
Which Indian philosopher elaborated on the doctrine of Parmanu and its existence in combined forms?
a) Maharishi Kanad
b) Pakudha Katyayama
c) Aristotle
d) Confucius
Answer: b) Pakudha Katyayama
What did Maharishi Kanad and Pakudha Katyayama believe about the divisibility of matter?
a) Matter can be divided into infinite particles
b) Matter cannot be divided at all
c) Matter can be divided until we reach the smallest particles called Parmanu
d) Matter can be divided until we reach the atomic level
Answer: c) Matter can be divided until we reach the smallest particles called Parmanu
In which civilization did these ancient philosophers speculate about the smallest particles of matter?
a) Ancient Egypt
b) Ancient China
c) Ancient India
d) Ancient Rome
Answer: c) Ancient India
Who were the ancient Greek philosophers who suggested the existence of indivisible particles called atoms?
a) Socrates and Plato
b) Aristotle and Pythagoras
c) Democritus and Leucippus
d) Hippocrates and Euclid
Answer: c) Democritus and Leucippus
What did Democritus call the indivisible particles?
a) Parmanu
b) Elements
c) Compounds
d) Atoms
Answer: d) Atoms
Who laid the foundation of chemical sciences by establishing two important laws of chemical combination?
a) Antoine L. Lavoisier
b) Isaac Newton
c) Albert Einstein
d) Marie Curie
Answer: a) Antoine L. Lavoisier
What were the two important laws of chemical combination established by Antoine L. Lavoisier?
a) Law of Gravity and Law of Thermodynamics
b) Law of Conservation of Mass and Law of Definite Proportions
c) Law of Motion and Law of Electric Charges
d) Law of Genetics and Law of Evolution
Answer: b) Law of Conservation of Mass and Law of Definite Proportions
Who stated the law of constant proportions, also known as the law of definite proportions?
a) Antoine L. Lavoisier
b) John Dalton
c) Proust
d) Democritus
Answer: c) Proust
Which scientist provided the basic theory about the nature of matter and introduced the concept of atoms?
a) Antoine L. Lavoisier
b) John Dalton
c) Proust
d) Democritus
Answer: b) John Dalton
What did John Dalton’s atomic theory explain?
a) The law of gravity
b) The law of thermodynamics
c) The law of conservation of mass and the law of definite proportions
d) The law of motion
Answer: c) The law of conservation of mass and the law of definite proportions
According to Dalton’s atomic theory, what are the smallest particles of matter called?
a) Parmanu
b) Elements
c) Compounds
d) Atoms
Answer: d) Atoms
In which year did John Dalton present his atomic theory?
a) 1766
b) 1793
c) 1808
d) 1824
Answer: c) 1808
According to Dalton’s atomic theory, what are the small particles that make up all matter called?
a) Molecules
b) Elements
c) Particles
d) Atoms
Answer: d) Atoms
According to Dalton’s atomic theory, what is the nature of atoms?
a) They are divisible particles.
b) They can be created or destroyed in a chemical reaction.
c) They are identical in mass and chemical properties.
d) They are large particles composed of multiple elements.
Answer: c) They are identical in mass and chemical properties.
According to Dalton’s atomic theory, what remains constant in a given compound?
a) The mass of atoms
b) The chemical properties of atoms
c) The number of atoms and their kinds
d) The ratio of atoms to molecules
Answer: c) The number of atoms and their kinds.
Who was the first scientist to use symbols for elements in a specific sense?
a) Antoine L. Lavoisier
b) John Dalton
c) Berzilius
d) Democritus
Answer: b) John Dalton
What did John Dalton’s use of symbols for elements represent?
a) Different isotopes of the element
b) Different compounds of the element
c) A definite quantity of the element, specifically one atom
d) Various physical properties of the element
Answer: c) A definite quantity of the element, specifically one atom.
Who suggested that symbols for elements should be made from one or two letters of the element’s name?
a) Antoine L. Lavoisier
b) John Dalton
c) Berzilius
d) Democritus
Answer: c) Berzilius
What was the purpose of using symbols for elements in chemistry?
a) To represent the different states of matter
b) To identify the atomic number of elements
c) To indicate the reactivity of elements
d) To simplify chemical equations and formulas
Answer: d) To simplify chemical equations and formulas
What does IUPAC stand for?
a) International Union of Pure and Applied Chemistry
b) International Union of Physics and Chemistry
c) International Unit for Practical Atomic Calculation
d) International Unit for Physical and Chemical Analysis
Answer: a) International Union of Pure and Applied Chemistry
What does IUPAC approve in the field of chemistry?
a) Names of compounds
b) Names of elements, symbols, and units
c) Scientific theories
d) Laboratory equipment
Answer: b) Names of elements, symbols, and units
According to Dalton’s atomic theory, what concept did he propose regarding each element?
a) Atomic number
b) Atomic radius
c) Atomic mass
d) Atomic charge
Answer: c) Atomic mass
How were relative atomic masses determined in Dalton’s time?
a) By measuring the mass of individual atoms
b) By using the laws of chemical combinations and the compounds formed
c) By using the atomic number of the element
d) By comparing the density of elements
Answer: b) By using the laws of chemical combinations and the compounds formed.
What is a molecule?
a) A single atom of an element
b) A group of atoms chemically bonded together
c) A large cluster of ions
d) An independent particle with no attractive forces
Answer: b) A group of atoms chemically bonded together
What is the primary characteristic of a molecule?
a) It consists of only one type of atom.
b) It consists of a large number of atoms.
c) It is tightly held together by attractive forces.
d) It cannot exist independently.
Answer: c) It is tightly held together by attractive forces.
What do molecules and ions aggregate to form?
a) Atoms
b) Elements
c) Compounds
d) Matter that can be seen, felt, or touched
Answer: d) Matter that can be seen, felt, or touched.
Which of the following elements typically form diatomic molecules?
a) Metals
b) Nonmetals
c) Metalloids
d) Transition metals
Answer: b) Nonmetals
What is the atomicity of a molecule?
a) The atomic number of the element in the molecule
b) The total number of atoms in the molecule
c) The ratio of neutrons to protons in the molecule
d) The number of electrons in the molecule
Answer: b) The total number of atoms in the molecule
Which molecule is an example of a diatomic molecule?
a) Ar (argon)
b) He (helium)
c) O2 (oxygen)
d) O3 (ozone)
Answer: c) O2 (oxygen)
What are the charged species in compounds composed of metals and nonmetals called?
a) Molecules
b) Elements
c) Ions
d) Atoms
Answer: c) Ions
What is a negatively charged ion called?
a) An atom
b) A polyatomic ion
c) An anion
d) A cation
Answer: c) An anion
What is a positively charged ion called?
a) A polyatomic ion
b) An atom
c) An anion
d) A cation
Answer: d) A cation
In the compound sodium chloride (NaCl), what are the constituent particles?
a) Sodium atoms (Na)
b) Chlorine atoms (Cl)
c) Sodium ions (Na+) and chlorine ions (Cl–)
d) Sodium molecules (Na2) and chlorine molecules (Cl2)
Answer: c) Sodium ions (Na+) and chlorine ions (Cl–)
What is a group of atoms carrying a charge called?
a) An ion
b) A molecule
c) A polyatomic ion
d) An element
Answer: c) A polyatomic ion
What is the chemical formula of a compound?
a) A symbolic representation of its composition
b) The number of atoms in a compound
c) The arrangement of elements in a compound
d) The mass of a compound
Answer: a) A symbolic representation of its composition.
What is the combining power of an element known as?
a) Valency
b) Atomicity
c) Electronegativity
d) Molarity
Answer: a) Valency.
How can valency be used to determine the combination of atoms in a compound?
a) By counting the number of arms an atom has
b) By determining the number of valence electrons
c) By analyzing the atomic mass of the element
d) By calculating the molar mass of the compound
Answer: b) By determining the number of valence electrons.
