Consider the following intermediate chemical equations.
pe(s)+6012(g) →
4pci,(g) → p4(s)+10c12(0)
ah, --2,439 kj
ah2 = 3,438 kj
what is the enthalpy of the overall chemical reaction pcl.(g) → pci; (g) + cl2(g)?
-999 kj
-250. kj
250. kj
999 kj

Will give imagine you are given a mystery element. it is, however, a discovered and known element. you may perform a maximum of two observations or tests to determine its identity. time and money is critical, so you need to prioritize your tests. if you can get by with a single test, you get 100 super-geek points from your research lab team. pick your two tests, number them as #1 and #2, and justify why you think these two will certainly be enough (and why the first might well be enough all by itself.) the available tests are classification into metal, non-metal, or metalloid, count of valence electrons, count of electron shells, atomic radius (error range: +/- 1 pm), electronegativity (error range: +/- 0.1), first ionization energy (error range: +/- 10 kj/mole), melting point (error range: +/- 10 c), and boiling point (error range: +/- 20 c).