Physics · Grades 9–12
Atomic & nuclear models · Formula reference
Formula reference
Rule and assumptions
Expected amount after half-lives
This predicts the expected remaining amount for a large ensemble; individual decays are random.
N = N₀(½)ⁿ
Photon energy in a scaled unit
Track powers of ten; the answer is a coefficient in units of 10⁻¹⁹ J.
E = hf
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · independent educational and translation review required. Suggested grades are not official curriculum alignment.