Answer:
You not alone lolI'm also tryna figure out the answer
I think the answers are A, C, A.
Answer: penetration is the ability of an electron in a given orbital to approach the nucleus closely. Shielding refers to the fact that core electrons reduce the degree of nuclear attraction felt by the orbital electrons. Shielding is the opposite of penetration. The most penetrating orbital is the least screening orbital. The order of increasing shielding effect/decreasing penetration is s<p<d<f.
Explanation:
The order of penetrating power is 1s>2s>2p>3s>3p>4s>3d>4p>5s>4d>5p>6s>4f....
Since the 3p orbital is more penetrating than the 3d orbital, it will lie nearer to the nucleus and thus possess lower energy.
There are actually three: One oxygen atom and two hydrogen atoms.
A higher concentration of reactants leads to more collisions per unit time and leads to an increasing reaction rate. Changing the pressure of gaseous reactants is, in effect, changing their concentration. The increased number of collisions caused by a higher pressure generally increases the reaction rate.
