use the bond energies provided to estimate δh°rxn for the reaction below. xef2 2 f2 → xef6 δh°rxn = ? bond bond energy (kj/mol) xe-f 147 f-f 159

Elements that do not have full outer electron shells will donate, share, or take electrons from other atoms. choose the items that have the correct binary ionic formula.

Ican determine the molar mass of an element by looking on the under the atomic mass for the element. for example the molar mass of phosphorus is 30.974 grams/mole. avogadro’s number tells me the amount of representative particles in 1 mole of any substance. this means 12.011 gram sample of carbon and a 32.0 gram sample of sulfur have the same number of atoms.

Asample of tin (ii) chloride has a mass of 0.49 g. after heating, it has a mass of 0.41 g.  what is the percent by mass of water in the hydrate?   %