Identify the pairs among the following that are not isoelectronic: a. Cl- and Na+
b. Te2- and Ba2+
c. Ca2+ and Kr
d. Ar and Ca2+
e. Na+ and Al3+

2. how is heavy water different from normal water

What are scientists who study fossils called? ( a ) astronomers. ( b ) biologists. ( c ) geologists. ( d ) paleontologists.

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?