Chemistry STAAR Review

Front

What is a chemical reaction?

Back

A process where substances (reactants) undergo a transformation to form new substances (products), often involving changes in energy and mass.

Front

What are valence electrons?

Back

Electrons in the outermost shell of an atom that determine its chemical properties and reactivity.

Front

What is the difference between physical and chemical changes?

Back

Physical changes alter the form or appearance of a substance without changing its chemical composition, while chemical changes result in the formation of new substances.

Front

What is a molecule?

Back

A group of two or more atoms bonded together, representing the smallest fundamental unit of a chemical compound.

Front

What is the periodic table?

Back

A tabular arrangement of chemical elements, organized by increasing atomic number, which shows periodic trends in properties.

Front

What are metals, nonmetals, and metalloids?

Back

Metals are good conductors of heat and electricity, nonmetals are poor conductors, and metalloids have properties of both.

Front

What is the law of conservation of mass?

Back

In a chemical reaction, mass is neither created nor destroyed; the total mass of reactants equals the total mass of products.

Front

What is a compound?

Back

A substance formed when two or more different elements chemically bond together in fixed proportions.

Front

What is an enzyme?

Back

A biological catalyst that speeds up chemical reactions in living organisms, such as digestion.

Front

What is the role of peptidase in digestion?

Back

Peptidase enzymes break down proteins into smaller peptides and amino acids during digestion.