Last updated on August 30th, 2023 at 01:44 am
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.
