Which of the following pairs of elements would form a covalent compound? calcium/phosphorous
copper/fluorine
sodium/ sulfur
nitrogen/ oxygen

In this chemical reaction, 325 grams of barium (ba) react completely. how many moles of lithium (li) are produced?

In the cathode ray tube experiment, j. j. thomson passed an electric current through different gases inside a cathode ray tube in the presence of an electric field. in which two ways did this experiment change scientists’ understanding of the atom?

Consider the following reactions. (note: (s) = solid, (l) = liquid, and (g) = gas.) mg(s) + ½o2(g) → mgo(s) + 146 kcal/mole h2(g) + ½o2(g) → h2o(g), δh = -57.82 kcal/mole what type of reaction is represented by the previous two examples?