4.) True:
Since
P(E) = 1 - P(Ec)
P(E)+P(Ec)=1
If you think of it as the chances of you getting e or not getting e, then it's a 100% chance of either one happening.
Zirconium cannot be broken down by a chemical change, because it is an element. The others are all molecules.
Answer:It has the lowest effective nuclear charge of the four new elements.
