All of the following increase from left to right across the second period of the periodic table (na - ar) except

effective nuclear charge
number of core electrons
number of valence electrons
atomic number

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.

Which statement best describes what happens when molecular compounds melt

How many moles are in 123.0 grams of kclo4?