3. Neutrons & Isotopes

You learned that when you change the number of protons of an atom, the identity of the atom changes. Take a look at what happens when the number of neutrons changes.

CONNECT:

Directions:

Watch the video to learn more about how changes in the number of neutrons affect the atom.

As the video plays, you will be asked some questions to self-assess your understanding.

Feel free to watch the video again.

The number of neutrons determines the isotope. Isotopes have different masses because the mass number depends on the number of protons and number of neutrons.

Mass number = Number of protons + Number of neutrons

EXAMPLE:

Count the number of protons and neutrons of each carbon isotope.

Remember that the mass of the electrons does not count as it is very very very small.

Isotopes are presented in isotope notation, which is as follows:

name of element, dash, mass number

RESEARCH:

In your portfolio, research an element of your choice to answer the following questions:

1. How many isotopes of that element exist?

2. What are the number of protons and neutrons of each isotope?

3. Which isotope has the greatest mass number?

4. Which isotope is the most stable?

5. What are the similarities and differences of isotopes of the same element? Add at least one new vocabulary word to your portfolio.