2. Atomic Particles Proton Neutron Electron - + N Protons and Neutrons together are called Nucleons
3. Atomic Number is the number of Protons Atomic Mass is Protons and Neutrons together
4. Proton Positively charged particle Resides in the nucleus Weighs 1 Atomic Mass Unit (AMU) Repel other protons The number of protons determines the element number. +
5. Proton Positively charged particle Resides in the nucleus Weighs 1 Atomic Mass Unit (AMU) Repel other protons The number of protons determines the element number. + Which element would this be? + + + + +
6. Proton Positively charged particle Resides in the nucleus Weighs 1 Atomic Mass Unit (AMU) Repel other protons The number of protons determines the element number. + Which element would this be? Carbon + + + + +
7. Too Many Protons Protons repel each other due to the electromagnetic force If an element has too many protons, it will be unstable and will break apart. + +
8. Too Many Protons This is why all elements over #82 Lead are radioactive! In addition, none over #94 Plutonium exist naturally. + +
9. Neutron N A Neutron has a neutral charge Neutrons weigh 1.001 AMU Resides in the nucleus It does not affect the elemental or chemical properties of the atom
10. Neutron A Neutron has a neutral charge Neutrons weigh 1.001 AMU Resides in the nucleus It does not affect the elemental or chemical properties of the atom It does provide additional nuclear force to hold the nucleus together N
11. Isotopes Isotopes result from different numbers of neutrons in an element Isotopes are chemically the same They only differ in their mass and their nuclear stability N + N N + N N + + N + + + + N N N N N + N + + + N N Carbon-12 C12 Carbon-14 C14
12. Strong Nuclear Force The strong nuclear force is the force that holds the nucleus together. All Nucleons are attracted to each other. Because + protons repel each other (electromagnetic force), the presence of neutrons helps bind the nucleus together. Electromagnetic Force + N N N + + Strong Nuclear Force Strong Nuclear Force Strong Nuclear Force
13. Atomic Stability The more protons there are, the more neutrons are necessary to stabilize the nucleus. Note that Helium has 2p/2n ratio Lead has 82p/125n ratio 2 82 Pb He 4 207 Helium Lead
14. Atomic Mass Atomic mass is the average of all isotopes on Earth together. To figure out the number of neutrons, just go AtomicMass-Atomic # = Neutrons He 4-2=2 neutrons Pb 207-82 = 125 neutrons 2 82 Pb He 4 207 Helium Lead
15. Atomic Stability The more protons there are, the more neutrons are necessary to stabilize the nucleus.
16. Electrons Electrons are negative particles Electrons weight 0.001 AMU They reside outside the nucleus in the electron cloud They usually match the number of protons to make a neutral atom -
17. This is the relative scale + - Except the proton should be 10x bigger!
19. What is a Neutron Anyways? OK, so you’ve heard that Neutrons are neutral and weigh 1.001 AMU Do you notice any pattern here?
20. What is a Neutron Anyways? Think of a Neutron as a Proton and Electron stuck together.
21. What is a Neutron Anyways? Think of a Neutron as a Proton and Electron stuck together. N
22. Beta Decay? When an isotope has too many neutrons, a neutron will emit a β-particle (which is basically an electron) This causes the neutron to change from neutral to positive (i.e. a proton). This actually changes the element it is!
28. Energy Levels When energy is added, electrons can jump to higher energy shells. When that electron returns to its normal state, that energy is released (often as light). That is how a fluorescent or neon light works. Electricity is exciting air molecules
30. Heisenburg Uncertainty Principal Heinsenburg realized it is impossible to knkow both an electrons position and velocity at the same time. That is because the moment you detect its position, you have changed its velocity – and vice-versa.
32. Why the uncertainty? You know where it was, but now you have changed its direction and speed.
33. Quantum Mechanics Probability densities The electrons do not appear to move in patterns, but simply seem to flash on and off in different locations. It is described as being almost like a instantaneous transporter
