Chem Midterm A

Front

What is the primary function of electrons in chemical reactions?

Back

They bond atoms together to form molecules.

Front

What is the half-life of a substance?

Back

The time required for half of the substance to decay.

Front

If the half-life of Zn-71 is 2.4 minutes, how much of a 100.0 g sample remains after 7.2 minutes?

Back

12.5g

Front

Which subatomic particle determines the identity of an element?

Back

Proton

Front

Who discovered the electron?

Back

J.J. Thomson

Front

What is an isotope?

Back

Atoms of the same element with different numbers of neutrons.

Front

What does it mean for an isotope to decay?

Back

It naturally transmutes into another element or isotope.

Front

What is the charge of a proton?

Back

Positive.

Front

What is the charge of an electron?

Back

Negative.

Front

What is the charge of a neutron?

Back

Neutral.