CHEMISTRY TEST SPRING 2025

Front

What is the only noble gas that does not have 8 valence electrons?

Back

Helium (He) has 2 valence electrons.

Front

What is NaHCO₃ an example of?

Back

NaHCO₃ is an example of a compound.

Front

What type of reaction is represented by BC -> B + C?

Back

This is a decomposition reaction.

Front

In the formula 4CF₂Cl₂, how many atoms of each element are present?

Back

C = 4, F = 8, Cl = 8.

Front

Is the equation Al + O₂ → 2Al₂O₃ balanced?

Back

No, the equation is not balanced.

Front

What are valence electrons?

Back

Valence electrons are the electrons in the outermost shell of an atom that are involved in chemical bonding.

Front

What is a compound?

Back

A compound is a substance formed when two or more elements chemically bond together.

Front

What is a decomposition reaction?

Back

A decomposition reaction is a type of chemical reaction where one compound breaks down into two or more simpler substances.

Front

What is the significance of balancing chemical equations?

Back

Balancing chemical equations ensures that the law of conservation of mass is obeyed, meaning the number of atoms of each element is the same on both sides.

Front

What is the difference between a mixture and a compound?

Back

A mixture is a combination of two or more substances that are not chemically bonded, while a compound is a substance formed from two or more elements that are chemically bonded.