1. Parts of an Atom
UNIT 1 NOTES

2. What does an atom look like?

3. Remember Jimmy Neutron?
Is this an accurate representation of an atom?

4. Atoms - the building blocks of matter
What are atoms?
Atoms - the building blocks of matter Li Li

5. Matter - anything that has mass and volume
Structure of Matter
Matter - anything that has mass and volume

6. Atomic Structure
Atom - the smallest particle of an element, having all the properties of that element

7. Atomic Structure
Subatomic Particles - any particle that is smaller than an atom (over 200 kinds are known)

8. Atomic Structure
Nucleus - very small, dense, positively charged center of an atom
Makes up approximately 99% of an atom’s mass, but a very small amount of its volume

9. Atomic Structure: Inside the Nucleus
The nucleus is made up of…
Protons - subatomic particles with a positive charge (proton = positive)
Neutrons - subatomic particle with no charge (neutron = neutral)

10. Atomic Structure
Electrons - subatomic particles with a negative charge
Orbit the atom’s nucleus

11. Electron cloud - the space in which electrons are likely to be found
Atomic Structure
Electron cloud - the space in which electrons are likely to be found

12. Periodic Table - Contains information about each of the elements

13. Periodic Table
Elements on the periodic table are each uniquely defined by their atomic number (number of protons)

14. Periodic Table: Elements
Atomic Number - Equal to the number of protons in the nucleus, as well as the number of electrons in the electron cloud
Symbol - A one or two letter abbreviation derived from the element’s English or Latin name
Name - Element’s common name
Atomic Mass - Weighted average of the masses of all the element’s isotopes

15. ATOMIC MASS = # PROTONS + # NEUTRONS
What is the atomic mass?
Atomic Mass - Weighted average of the masses of all the element’s isotopes
Nucleus is 99% of the mass of the atom
Nucleus is made up of protons and neutrons
This means that the mass of the atom is approximately equal to the mass of the protons plus the neutrons
Mass of proton = 1 atomic mass unit (amu)
Mass of neutron = 1 atomic mass unit (amu)
ATOMIC MASS = # PROTONS + # NEUTRONS

16. Summary Atomic Number = Number of protons
Atomic Number = Number of electrons
Symbol = Big letter(s) in the center
Name = Name of element
Atomic Mass = Number of protons plus number of neutrons