Pre-AP/IB Chemistry Review

Front

What does the Periodic Law state?

Back

The Periodic Law states that the elements are arranged according to their atomic numbers so that elements with similar chemical properties are in the same column and properties repeat periodically.

Front

How many valence electrons are in the third energy level of an element with 18 electrons?

Back

18 valence electrons are in the third energy level.

Front

What is an endothermic process?

Back

An endothermic process is a reaction or change that absorbs energy or heat from its surroundings.

Front

What is a physical change? Give an example.

Back

A physical change is a change that affects one or more physical properties of a substance without altering its chemical composition. Example: Melting ice.

Front

What is the name of an ion with a positive charge?

Back

Cation.

Front

What is the definition of atomic number?

Back

The atomic number is the number of protons in the nucleus of an atom, which determines the element's identity.

Front

What is the difference between an ionic bond and a covalent bond?

Back

An ionic bond is formed when electrons are transferred from one atom to another, while a covalent bond is formed when two atoms share electrons.

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.

Front

What is a chemical change? Give an example.

Back

A chemical change is a change that results in the formation of new chemical substances. Example: Burning wood.

Front

What is the definition of a mole in chemistry?

Back

A mole is a unit of measurement used to express the amount of a substance, defined as containing exactly 6.022 x 10^23 particles (atoms, molecules, etc.).