Unit 4: Atomic Structure
Reading
BJU Chemistry: Ch. 4 "Atomic Structure"
AP Classroom will begin Unit 3 'Substances and Mixtures'
Topics
Labs
BJU Chemistry: Ch. 4 "Atomic Structure"
AP Classroom will begin Unit 3 'Substances and Mixtures'
Topics
- Structure of the atom
- Electron configurations
- Atomic number and atomic mass
- Isotopes
- Ions
Labs
- Oxygen lab: Prepare and test oxygen gas
- Build-an-Atom weblab
Oxygen lab
We will make and test oxygen gas. This is a classic lab, making and collecting an atmospheric gas, and testing it under different conditions. Remember to bring the lab handout!
We will make and test oxygen gas. This is a classic lab, making and collecting an atmospheric gas, and testing it under different conditions. Remember to bring the lab handout!
| o2_lab_handout.pdf |
Build-an-Atom Weblab
| 3._build-an-atom_weblab.doc |
Videos of standing waves
It's difficult to picture electrons as 'waves' which must occupy discrete 'orbitals' or energy-levels. If you think this is confusing, you're not alone!
The vibrating "Chlodni" plates (below) might help you visualize what standing waves look like - at least in 2 dimensions anyway. As the vibration frequency is increased in the videos (representing more and more energy input), the salt crystals arrange themselves at the wave "nodes". The steel plate vibrates as a wave, and the salt can only exist at the nodes, where there is no vibration.
In the same way, electrons can occupy only "discrete" orbitals - or energy levels - around an atom. They can't just sit anywhere they want; they must occupy discrete energy levels (orbitals or shells) which are numbered 1s, 2s, 2p, etc.
When you add energy (light of a certain wavelength, for example) to an atom, the electrons can jump up to a higher orbital. Conversely, when electrons jump down a level, light energy is emitted from the atom.
It's difficult to picture electrons as 'waves' which must occupy discrete 'orbitals' or energy-levels. If you think this is confusing, you're not alone!
The vibrating "Chlodni" plates (below) might help you visualize what standing waves look like - at least in 2 dimensions anyway. As the vibration frequency is increased in the videos (representing more and more energy input), the salt crystals arrange themselves at the wave "nodes". The steel plate vibrates as a wave, and the salt can only exist at the nodes, where there is no vibration.
In the same way, electrons can occupy only "discrete" orbitals - or energy levels - around an atom. They can't just sit anywhere they want; they must occupy discrete energy levels (orbitals or shells) which are numbered 1s, 2s, 2p, etc.
When you add energy (light of a certain wavelength, for example) to an atom, the electrons can jump up to a higher orbital. Conversely, when electrons jump down a level, light energy is emitted from the atom.
| ch._4_atomic_structure_exercises_-_student_exemplar.pdf |
| ch._4_atomic_structure_exercises_tips_notes.docx |
| 4._build-an-atom_weblab_student_example.doc |