Atomic Structure Basics
Think of atoms like a block of flats - electrons live in different floors (shells) with specific rooms (orbitals). Electron configuration tells us exactly where each electron lives, and it's not random at all.
Shells are divided into sub-shells (s, p, d, f), and each sub-shell contains orbitals - regions where you're most likely to find an electron. Each orbital can hold a maximum of 2 electrons, but they must have opposite spins (think of them as spinning in different directions).
The Aufbau principle is your best friend here - electrons always fill the lowest energy orbitals first. Remember the capacities: s holds 2 electrons, p holds 6, and d holds 10. It's like filling up the cheapest seats at a concert before moving to the expensive ones!
Quick Tip: Draw the energy level diagram - it shows you exactly which orbitals fill in which order, and you'll use this constantly in exams.
