Calculate the lattice energy for naf (s) given the following

sublimation of energy +109 kj/mol

hf for f (g) + 77 kj/mol

first ionization energy of na (g) +495

electron affinity of f(g) -328

enthalpy of formation of naf(s) -570 kj/mol

a. -177

b. 192

c. -804

d. -1047

e. -923

This active feature of earth's crust in building mountain ranges as well as islands. this feature is a a) cavern. b) earthquake. c) mountain. d) volcano.

What was bohr’s contribution to the planetary model

Acalorimeter is to be calibrated: 51.203 g of water at 55.2 degree c is added to a calorimeter containing 49.783 g of water at 23.5c. after stirring and waiting for the system to equilibrate, the final temperature reached is 37.6 degree c. specific heat capacity of water (s = 4.18 j/g∙degree c). calculate the calorimeter constant. (smδt)warm water = -[(smδt)cold water + (calorimeterδtcold water)]