1. Atomic Structure

2. Atom
Basic unit of matter
Made of subatomic particles

3. Element
Substance made of same type
of atom

4. Protons Positive Charge Located in the nucleus Mass = 1 amu
Helps make up the mass of an atom
# of protons never changes for an element
Same as atomic number

5. Neutrons No Charge Located in the nucleus Mass = 1 amu
Helps make up the mass of an atom
Can differ in atoms of the same element
How to Calculate Neutrons
Mass # - Atomic # = Neutrons

6. Electrons Negative Charge Located in the electron cloud Mass = 0 amu
Surrounds the nucleus
Move very fast!
Mass = 0 amu
Does not really count towards an atom’s mass
In neutral atoms, electrons = protons

7. Atomic Number Special for every element
Tells # of protons (and electrons)
Located on the periodic table (whole number)

8. Atomic Mass Located on periodic table
Has decimals
Average mass of the element’s isotopes

9. Mass Number
Protons + Neutrons
Whole Number (rounded atomic mass)

10. Practice
How many protons does nitrogen have?

11. Practice
What is the atomic mass of calcium?

12. Practice
What is the mass number of calcium?

13. Practice
How many neutrons are in chlorine?

14. Practice Name of Element: Atomic Number: Atomic Mass: Mass Number:
Protons:
Neutrons:
Electrons:

15. Practice Name of Element: Atomic Number: Atomic Mass: Mass Number:
Protons:
Neutrons:
Electrons:

16. Practice Name of Element: Atomic Number: Atomic Mass: Mass Number:
Protons:
Neutrons:
Electrons:

17. Just How Small Are Atoms?

18. Isotopes
Same element with different numbers of neutrons; therefore, different masses
EX: Carbon-12 Carbon-14
6 12 C C

19. Practice How many neutrons in Potassium-39 Potassium-41 Fluorine-19

20. Practice
Ni-60
Protons?
Electrons?
Mass number?
Neutrons?

21. Practice
Magnesium-26
Protons?
Electrons?
Mass number?
Neutrons?

22. Practice P
Protons?
Electrons?
Mass number?
Neutrons?

23. Ions Charged atom Gain or lose 1 or more electrons
Proton number does not change

24. Practice How many electrons in a neutral atom of Na?
How many protons in Na?
How many electrons in Na +1

25. Practice How many electrons in a neutral atom of S?
How many protons in S?
How many electrons in S -2?