1. A diffraction grating with 5.000 x 103 lines/cm is used to examine the sodium
spectrum. Calculate the angular separation of the two closely spaced yellow lines
of sodium (588.995 nm and 589.592 nm) in each of the first three orders.

Sublimation- which change of state is shown in model

Answerthe energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.explanationwe define electric potential as the ratio electric potential energy to the charge,    then the following gives us the potential difference,      the formula  may be on your formula sheet.the change in electric potential energy would be the energy that would needed to move it from point a to point b. solving for that, we get    using q = 8.00  × 10⁻¹⁹ c and  δv = 2.00 v, we get    the energy required is 1.60 × 10⁻¹⁸ j, to three significant figures.

Answer (d) the universe had cooled enough for atoms to combine, protons and neutrons were too far apart to form nuclei;