Use the given heats of formation to calculate the enthalpy change for this reaction. B2O3(g) + 3COCl2(g) →2BCl3(g) + 3CO2(g) ΔHof of B2O3(g) is –1272.8 kJ∙mol–1 ΔHof of BCl3(g) is –403.8 kJ∙mol–1 ΔHof of COCl2(g) is –218.8 kJ∙mol–1 ΔHof of CO2(g) is –393.5 kJ∙mol–1 Question 8 options: 1) 649.3 kJ·mol–1 2) 354.9 kJ·mol–1 3) –58.9 kJ·mol–1 4) –3917.3 kJ·mol–1

An atom of sodium-23 (atomic number = 11) has a positive charge of +1. give this information, how many electrons does it have? how many proteins and neutrons does this atom have

Me i dont know what to do! the table compares the number of electrons in two unknown neutral atoms. comparison of electrons atom number of electrons a 10 d 11 use this information to determine the number of valence electrons in the atoms. which of the following correctly compares the stability of the two atoms? both are unreactive. both are highly reactive. a is unreactive and d is reactive. a is reactive and d is unreactive.

Which explanation is true about what happens to a ray of light when it strikes a mirror? a. a light ray is transmitted toward a mirror at a certain angle. the light ray is then reflected by the mirror at an equal angle but in the opposite direction of the transmitted ray. b. an incident ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then reflected at an angle equal to the angle of incidence but on the opposite side of the perpendicular line. c. a reflecting ray strikes a mirror at an angle with a line perpendicular to the mirror. the light ray is then refracted at an angle equal to the angle of the reflecting ray and on the same side of the perpendicular line. d. an incident ray strikes a mirror at an angle with a line parallel to the mirror. the light ray is then transmitted at an angle equal to the angle of incidence but on the opposite side of the parallel line. you so much! : -d take the time to try and answer correctly.