Chemistry Semester Exam Clark HS 2024

Front

What is a covalent compound?

Back

A covalent compound is a chemical compound formed by the sharing of electrons between atoms. Example: H₂S (Hydrogen Sulfide).

Front

How do you calculate the number of atoms in a mole?

Back

To calculate the number of atoms in a mole, use Avogadro's number (6.022 x 10²³). For example, 6.3 mol of Zn contains 6.3 x 6.022 x 10²³ = 3.8 x 10²⁴ atoms Zn.

Front

What is a cation?

Back

A cation is a positively charged ion, formed when an atom loses one or more electrons. Example: Na⁺ (Sodium ion).

Front

What is an anion?

Back

An anion is a negatively charged ion, formed when an atom gains one or more electrons. Example: Cl⁻ (Chloride ion).

Front

How do you determine the number of neutrons in an isotope?

Back

To find the number of neutrons in an isotope, subtract the atomic number (number of protons) from the mass number. Example: Potassium-39 has 39 (mass number) - 19 (atomic number) = 20 neutrons.

Front

What is the difference between ionic and covalent bonds?

Back

Ionic bonds involve the transfer of electrons from one atom to another, resulting in charged ions. Covalent bonds involve the sharing of electrons between atoms.

Front

What is Avogadro's number?

Back

Avogadro's number is 6.022 x 10²³, which is the number of atoms, molecules, or particles in one mole of a substance.

Front

What is the significance of the periodic table in chemistry?

Back

The periodic table organizes elements based on their atomic number, electron configuration, and recurring chemical properties, helping predict element behavior.

Front

What is a molecule?

Back

A molecule is a group of two or more atoms bonded together, representing the smallest fundamental unit of a chemical compound. Example: H₂O (Water).

Front

What is the law of conservation of mass?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction; it remains constant.