BS Chemistry Fundamentals 1 — Questions and Answers
Question 1: What is an atom?
- The smallest unit of an element that retains the chemical properties of that element (Correct answer)
- A molecule consisting of two or more elements bonded together
- A subatomic particle found in the nucleus
- A compound formed by ionic bonding
Correct answer: The smallest unit of an element that retains the chemical properties of that element
An atom is the smallest particle of an element that still has the chemical characteristics of that element.
Question 2: What determines the atomic number of an element?
- The number of protons in the nucleus (Correct answer)
- The number of neutrons in the nucleus
- The total number of protons and neutrons
- The number of electrons in the outer shell
Correct answer: The number of protons in the nucleus
The atomic number uniquely identifies an element and equals the number of protons in the nucleus of an atom of that element.
Question 3: What is a covalent bond?
- A chemical bond formed by the sharing of electrons between atoms (Correct answer)
- A bond formed by the transfer of electrons from one atom to another
- An attraction between oppositely charged ions
- A weak intermolecular force between molecules
Correct answer: A chemical bond formed by the sharing of electrons between atoms
Covalent bonds form when two atoms share one or more pairs of electrons to achieve stable electron configurations.
Question 4: What is pH a measure of?
- The concentration of hydrogen ions in a solution (Correct answer)
- The concentration of hydroxide ions in a solution
- The buffering capacity of a solution
- The total dissolved solids in a solution
Correct answer: The concentration of hydrogen ions in a solution
pH is a scale measuring the acidity or alkalinity of a solution based on the concentration of hydrogen ions (H+).
Question 5: What is a chemical reaction?
- A process in which substances are transformed into different substances by breaking and forming chemical bonds (Correct answer)
- A change in the physical state of a substance without altering its composition
- The mixing of two substances without any bond changes
- The dissolution of a solid in a liquid
Correct answer: A process in which substances are transformed into different substances by breaking and forming chemical bonds
A chemical reaction involves the rearrangement of atoms to form new substances with different properties than the reactants.
Question 6: What is the law of conservation of mass?
- Matter cannot be created or destroyed in a chemical reaction (Correct answer)
- The mass of a substance decreases when it is heated
- Chemical reactions always produce products heavier than reactants
- Energy and mass are interchangeable in chemical reactions
Correct answer: Matter cannot be created or destroyed in a chemical reaction
The law of conservation of mass states that the total mass of reactants equals the total mass of products in a chemical reaction.
BS Chemistry Fundamentals 1
What is an atom?