8th Grade Fall Semester Exam

Front

What is a black hole?

Back

A region in space where the gravitational pull is so strong that nothing, not even light, can escape from it.

Front

How are mixtures combined?

Back

Mixtures are physically combined, not chemically.

Front

What is the pH value of a neutral substance?

Back

7

Front

What is the correct order of waves on the electromagnetic spectrum from low to high energy?

Back

Radio, Micro, Infra, Visible, Ultra, X-ray, Gamma.

Front

What is a pure substance that is a compound?

Back

A substance made of two or more elements that are chemically bonded together.

Front

What is the definition of a supernova?

Back

A supernova is a powerful and luminous explosion of a star, marking the end of its life cycle.

Front

What is the difference between a pure substance and a mixture?

Back

A pure substance has a uniform and definite composition, while a mixture contains two or more substances that are not chemically combined.

Front

What is the definition of a nebula?

Back

A nebula is a giant cloud of dust and gas in space, often the birthplace of stars.

Front

What is the significance of the pH scale?

Back

The pH scale measures how acidic or basic a substance is, with 7 being neutral.

Front

What are the three states of matter?

Back

Solid, liquid, and gas.