State where in the periodic table these elements appear: (a) elements with the valence-shell electron configuration ns2np5 (b) elements that have three unpaired p electrons (c) an element whose valence electrons are 4s24p1 (d) the d-block elements [Section 6.9]

Video transcript

hey everyone in this example, we need to determine which of the below statements is a true statement. So our first statement states that an element with a valence shell electron configuration of Ns two, NP three belongs to Group seven A. So when we look to our periodic tables And we see the configuration for n. s. two, we don't know the energy level, which is why they're labeling it n. However, we know that we have fully filled in our S sublevel and then we move to our next unknown energy level in the P block where they only fill in for three units. And we would recognize that if we count three units in our p sublevel or just count the first three atoms in the P sub level, we would land on the atom. Either nitrogen or phosphorus. If we begin at the third period or the fourth or sorry, the second period or the third period on our periodic tables when counting our P sub level. And we can recognize that nitrogen and phosphorus are both in Group five A. Which is also known as group 15. So we would go ahead and rule out choice one because it's not a true statement. They're stating that this configuration would correspond to group seven A. Which is not true. So this is going to be false. So moving on to statement two, it says that an element with two unpaid p electrons belongs to group 14. So that would correspond to the configuration being something like n. P. two, meaning we would only count for two units when in the P sub level on our periodic tables or the P block. And we would agree that if we count for two units starting either at period two or period three of our periodic tables, we would land on the atoms either carbon, carbon or silicon in period three. And this would correspond to those atoms being in group four A. Which we also recognize as group 14. So statement two is true but let's move on to see if any of the other given statements are true. Moving on to statement three, it says that an element with a valence electron of three. S. 23, P five belongs to Group one A. So when we go ahead and starting out with our outermost energy level which is going to be the energy level with the higher sub level being R P sub level. Because we recall that R. P sublevel is larger than our S sub level. When we go to the P block or piece of level on our periodic tables and count for five units. Since we have that exponent five, we would land in group seven A. If we start out at the third period In our p. block and counter five units. We would land specifically on the atom chlorine Which we recognize is in group seven a. Meaning that statement three is also false. It needs to be corrected to seven a. So we can rule it out. And lastly we have statement for which states that an element in the F Block belongs to group nine. And we would recall that R. F block begins at the fourth energy level, so we would have four F. And it also extends to the fifth energy level being five F. And we should recall that The sub levels four f and five f Correspond to being in group three. So we would actually go ahead and correct this to group three. And we would rule out choice For because it's a false statement. And that means that the only true statement given was statement to which states set an element with two unpaid p electrons belongs to group 14 Or group four a. So this is our final answer. If you have any questions, please leave them down below. Otherwise, I'll see everyone in the next practice video.