Summary
Highlights
Review of how to determine the number of protons, electrons, and neutrons for neutral atoms using the periodic table. Protons equal the atomic number, electrons equal protons in neutral atoms, and neutrons are found by subtracting protons from the mass number.
Explanation of electron configuration using a chart, noting that s-orbitals hold 2 electrons and p-orbitals hold 6. A detailed breakdown of the three subatomic particles: protons (positive, in nucleus, mass 1 amu), neutrons (neutral, in nucleus, mass 1 amu), and electrons (negative, in electron cloud, negligible mass).
How to extract information from the periodic table: atomic number for protons and electrons, atomic mass for calculating neutrons. Introduction to valence electrons as outermost electrons and their role in ionic and covalent bonding.
Differentiating between ionic bonds (metal transfers electron to non-metal) and covalent bonds (non-metal shares electrons with another non-metal). Examples of how to identify bond types based on the elements involved.
Instructions on creating Bohr models, where orbit number corresponds to row number and valence electrons to column number. Review of group numbers determining valence electrons and the formation of cations (positive ions from metals losing electrons) and anions (negative ions from non-metals gaining electrons).
Demonstration of electron transfer in ionic bond formation, using examples like potassium iodide and beryllium nitride. Explanation of the 'crisscross method' for determining chemical formulas and remembering that metals form positive charges and non-metals form negative charges to achieve a stable octet (magic number eight).
Clarification of groups (columns, valence electrons) and periods (rows, energy levels/shells). Definition of atom and element. Discussion of reactivity trends, with groups 1, 2, 6, and 7 being most reactive, and noble gases being inert. Atomic radius trends: size increases down a group and decreases across a period.
Examination of particle behavior when cooling: particles slow down, become more compact, and reduce spacing. Explanation of the Law of Conservation of Mass, stating that mass and atoms cannot be created or destroyed, ensuring equal mass and atom count on both sides of a chemical reaction.
Overview of different reaction types: double replacement, single replacement, synthesis (combining), and decomposition (breaking apart). Distinction between physical changes (appearance only, e.g., phase changes) and chemical changes (bonds breaking and re-forming into new substances).
Recap of essential concepts: atomic number equals protons, electrons are outside the nucleus, eight is the 'magic number' for stability (except hydrogen with two), how to count atoms in a chemical formula, and using group numbers to determine valence electrons.