Midterm Exam 2024

Front

What is a compound?

Back

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

Front

Which of the following is not a compound: HCl, Cl, NaCl, CO2?

Back

Cl is not a compound; it is an element.

Front

What is a chemical change?

Back

A chemical change occurs when substances combine or break apart to form new substances, often accompanied by bubbles, color change, or heat.

Front

What is a physical change?

Back

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

Front

What is a property of a compound?

Back

A property of a compound is that it has a fixed composition, meaning it contains the same particles throughout.

Front

Which of the following represents an element: H2O, H2, NaCl, CaCO3?

Back

H2 represents an element.

Front

What happens during a chemical reaction?

Back

During a chemical reaction, bonds between atoms are broken and new bonds are formed, resulting in the creation of new substances.

Front

What is the difference between a mixture and a compound?

Back

A mixture is a combination of two or more substances that retain their individual properties, while a compound is a substance formed from two or more elements that are chemically bonded.

Front

What is an example of a physical change?

Back

Melting ice is an example of a physical change.

Front

What is the definition of an element?

Back

An element is a pure substance that cannot be broken down into simpler substances by chemical means.