*62%*:**Students’ difficulties with solving bound and scattering state problems in quantum mechanics***57%*:**Students’ difficulties with partial differential equations in quantum mechanics***57%*:**Student difficulties with quantum states while translating state vectors in Dirac notation to wave functions in position and momentum representations***54%*:**Student Difficulties with the Dirac Delta Function***53%*:**Students’ metarepresentational competence with matrix notation and Dirac notation in quantum mechanics***49%*:**Categorization of quantum mechanics problems by professors and students***48%*:**Student evaluation of more or better experimental data in classical and quantum mechanics***46%*:**Upper-division student difficulties with the Dirac delta function***45%*:**Student Difficulties with Quantum Mechanics Formalism***44%*:**Framing difficulties in quantum mechanics***43%*:**Introductory students’ attitudes and approaches to Physics problem solving: Major, achievement level and gender differences***42%*:**Probing student reasoning in relating relative phase and quantum phenomena***40%*:**Investigating Student Difficulties with Dirac Notation***39%*:**Student Difficulties in Understanding Probability in Quantum Mechanics***39%*:**Surveying college introductory physics students’ attitudes and approaches to problem solving***39%*:**Using metacognitive prompts to explore student reasoning trajectories***38%*:**Student difficulties in learning quantum mechanics***38%*:**Categorization of Mechanics Problems by Students in Large Introductory Physics Courses: A Comparison with the Chi, Feltovich, and Glaser Study***38%*:**Conceptual and Mathematical Barriers to Students Learning Quantum Mechanics**