35 multiple-choice questions in College Board exam style. Each has four choices and a full explanation of why each option is right or wrong.
Remember photon energy depends on frequency, never intensity. This single fact resolves most photoelectric effect trick questions.
For nuclear decay, track both mass number and atomic number carefully. Alpha changes both, beta changes only atomic number, gamma changes neither.
For half-life problems, count the number of half-lives elapsed before calculating. Each half-life cuts the remaining amount by exactly half, regardless of how much time has already passed.
Read the explanations even when you got it right. Each one teaches a small fact that often returns in a different form on the exam.