Physical Science Final Review

Front

Atoms of the same element with different numbers of neutrons are called ___________.

Back

Isotopes

Front

How many electrons are needed in the outer energy levels of most atoms for the atom to be chemically stable?

Back

8

Front

According to the law of conservation of energy, the total amount of energy in the universe __________.

Back

Remains constant

Front

On the pH scale, a reading of ___________ represents basic substances.

Back

7.1-14

Front

How many grams of KBr are needed to make a saturated solution at 90°C?

Back

99 g

Front

What is the definition of an isotope?

Back

Atoms of the same element that have different numbers of neutrons.

Front

What is the significance of having 8 electrons in the outer energy level?

Back

It indicates that the atom is chemically stable.

Front

State the law of conservation of energy in simple terms.

Back

Energy cannot be created or destroyed, only transformed.

Front

What does a pH reading below 7 indicate?

Back

The substance is acidic.

Front

What is the pH of pure water?

Back

7