- Matter is made of atoms. Atoms consist of a dense nucleus containing protons (p+) and neutrons (n), and the electrons (e-) that “orbit” this nucleus.
- According to the Bohr model of the atom, electrons exist in discrete “orbits” (energy levels) around the nucleus of an atom. Each energy level can contain a maximum number of electrons (2, 8, 8, 18, 18, 32, 32,…). While current quantum-mechanical models of the atom are more accurate, the Bohr model is good enough to explain the phenomena we will observe in this course.
- Chemical properties of matter can be mostly explained by interactions between electrons and protons. The force a proton exerts on an electron is weaker when the particles are farther apart. Inner electrons also “shield” outer electrons from the nucleus, resulting in a weaker attraction between the nucleus and the electron. These two factors can be summarized by the concept of “electronegativity” – a measure of the ability of an atom to attract an electron in a chemical reaction.
- Each row of the periodic table contains a series of elements with the same number of core electrons. Each column of the periodic table contains a family of elements with the same number of outer electrons.
- Electronegativity is highest in the top-right corner of the periodic table. For the same reason, the largest atoms are in the bottom-left corner of the table. Low electronegativity = metallic.
- Identify the relative mass and charge of protons, neutrons, and electrons.
- Calculate the mass and charge of an atom based on its constituent particles.
- Draw the Bohr diagram of an atom that may be a strange isotope or ionized.
- Perform calculations involving scientific notation, to the correct level of precision.
- Calculate the effective nuclear charge of an atom, and draw conclusions about its electronegativity.
- Identify trends in atomic mass, volume, electronegativity, radioactivity, and reactivity in the periodic table.
- 1a.1 Electrostatics (pp 3-8 only)
- 1a.2 Atoms and their parts
- 1a.3 Atomic structure (long worksheet)
- 1a.4 Ions and subatomic particles (has answer key)
- 1a.5 Bohr model practice
- 1b.1 Significant figures
- 1b.2 Scientific notation
- 1b.3 Mass of an atom
- 1b.4 Effective nuclear charge & periodic trends
- 1b.5 Periodic table
Projects & Labs
- Point charge simulation
- Quiz 1a: Electrostatic force, subatomic particles, Bohr model
- Quiz 1b: Electronegativity; periodic table
- Test 1: Atoms