1. Comparing Atoms
Key Question:
How can you determine the number of protons, neutrons and electrons in an element?

2. How does one kind of atom differ from another?
Atoms are identified by the number of protons they have.
Adding or removing a proton changes the type of atom.

3. What can you learn from the atomic number?
The number of protons in an element is known as the atomic number.
The atomic number also tells the number of electrons in an atom.

4. What is the Atomic Mass Number?
The total number of protons and neutrons is called the atomic mass number.

5. What is an Isotope?
Isotopes = different atoms of the same element with different mass numbers.

6. Isotope Notation Mass Number and Atomic Number
An atom of carbon-12 has 6 protons
(the atomic number is 6), 6 neutrons
and 6 electrons.
Isotopes of carbon include
carbon-12
carbon-13
and carbon-14

7. How many neutrons are present in an atom of carbon with a mass number of 14?
You are asked for the number of neutrons.
You are given that it is carbon-14
The relationship is n + p = mass number
Solve for n.
n = mass number – p
Plug in numbers and get answer
n = 14 – 6 = 8 neutrons

8. What is an Ion? Ions are charged atoms How do Ions form?
Ions are formed by loosing or gaining electrons.

9. Conclusion
How can you determine the number of protons, neutrons and electrons in an element?

10. That’s all the notes for today