Unit 1 Exam Review

Front

Can a chemist determine compounds in a sample consisting of KO3 and K2O3 by knowing the mass of K?

Back

Yes, because the percent mass can be calculated and is unique for each compound.

Front

By the law of multiple proportions, two compounds have:

Back

different masses or percent masses.

Front

Which of the following represents an impossible electron configuration: a) 1s2 2s2 2p6 b) 1s2 2s2 2p5 3s1 c) 1s2 2s3 2p5?

Back

c) 1s2 2s3 2p5.

Front

What observation provides the best evidence that a change is physical rather than chemical when a solid melts?

Back

The solid and liquid phases coexist at a constant temperature during melting.

Front

Atoms or ions having the same electronic structure are called:

Back

isoelectronic.

Front

What is the definition of percent mass in a compound?

Back

The percent mass is the mass of a specific element in a compound divided by the total mass of the compound, multiplied by 100.

Front

What does the law of conservation of mass state?

Back

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction.

Front

What is an electron configuration?

Back

An electron configuration is the distribution of electrons in an atom's orbitals.

Front

What is the significance of the octet rule in chemistry?

Back

The octet rule states that atoms tend to gain, lose, or share electrons to achieve a full outer shell of eight electrons.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change alters the form of a substance but not its chemical composition, while a chemical change results in the formation of new substances.