Which one of the equations below is an endothermic reaction?
A) Sro (s) + CO, (9) - SrCO, (S)AH° = -234
KJ/mol
B) H2(g) + F2 (g) 2 HF (9) AH° = -79.2
KJ/mol
C) H2 (9) + C (s) + N, (g) - 2 HCN (9) AH° =
270.3 kJ/mol
D) 2 K (s) + 2 H20 (1)
AH° = -393.1 kJ/mol
2 KOH (aq) + H2 (9)

The blackbody curve for a star name zeta is shown below. what is the peak wavelength for this star ?

Use this information to determine the number of calends electrons in the atoms. which of the following correctly compares the stability of the two atoms? a) both are unreactive b) both are highly reactive c) a is unreactive and d is reactive d) a is reactive and d is unreactive

What is the solubility-product constant of barium sulfate, baso4, if a saturated solution is 1.03 ´ 10-5 m?