Calculate the lattice enthalpy of potassium fluoride from the following data. enthalpy of formation of k(g): +89 kj · mol−1 first ionization energy of k(g): +418 kj · mol−1 enthalpy of formation of f(g): +79 kj · mol−1 electron affinity of f(g): +328 (∆h = −328) kj · mol−1 enthalpy of formation of kf(s): −567 kj · mol−1

Aballet student who learns with the of his instructor is demonstrating learning.

The solar panels used by mark function because of the photoelectric effect. light shines on the cells causing electrons to be ejected from the metal, which produces an electric current. at night on mars, no light will fall on the solar cells and no electric current will be generated. according to your notes, what type of light is typically needed to cause the photoelectric effect? a)visible b)ultraviolet c)infrared

Which of the choices below is one of the primary gases found in the atmosphere? a. helium b. carbon dioxide c. nitrogen d. argon