CHEM 6A Exam 2-Form C Fall 2023 Multiple Choice

CHEM 6A Exam 2-Form C Fall 2023 Multiple Choice - Choose the BEST Answer Ar 19. Element A has a ground state electron configuration of $1s^2 2s^2 2p^6 3s^2 3p^6$ while Element B has a ground state electron configuration of $1s^2 2s^2 2p^6 3s^2 3p^5$. Which of the following statements is true regarding these elements? cl A) The ionization energy of A is lower than the ionization energy of B. B) When atom B gains an electron, it would release more energy than when atom A gains an electron. C) Element B usually forms a cation. D) Element A has a larger atomic radii than element B. E) More than one of the previous statements is true. 20. Which period 3 element could have the following successive ionization energies? $I_1 = 1,012 \text{ kJ/mol}$ $I_2 = 1,097 \text{ kJ/mol}$ $I_3 = 2,914 \text{ kJ/mol}$ $I_4 = 4,964 \text{ kJ/mol}$ $I_5 = 6,274 \text{ kJ/mol}$ $I_6 = 21,268 \text{ kJ/mol}$ $I_7 = 25,431 \text{ kJ/mol}$ Jual cnie A) Mg B) P C) Al D) Si E) S

Transcript

00:02 Hi there.

00:03 In this question, we have some statements about electron configurations.

00:07 So before we start, i just want to remind you that as we look at the periodic table, the first two columns are referred to as the s block elements, because they end with s1 and s2.

00:20 So the first group, every element there ends with an s1.

00:23 In the second group, every element ends with an s2.

00:27 The six groups over here to the right are the p block, with the exception of helium, because helium only has two electrons.

00:35 But the others are the p block, and their configurations end with p1 through p6, in order of the groups there.

00:44 The transition metals are the d block, and they are always one energy level behind the s and the p.

00:52 And then the two removed columns, those inner transition metals, are the f block elements.

00:58 Those ones that can hold up to 14 electrons.

01:02 Okay, so let's go ahead and get started looking at our questions here.

01:06 It says the element of the ground state configuration, and it ends with 3s1.

01:12 So if we number our periods here, something that ends with 3s1, we look at period 3, and we look at the s1 group.

01:25 So it's going to be right here, and that is an alkali metal.

01:30 The first group on the periodic table are the alkali metals.

01:33 So the first statement is true.

01:36 The next statement, ground state configuration for copper.

01:41 This one is incorrect.

01:43 Copper is right here.

01:48 And it has an exceptional electron configuration or one that does not follow the general rules.

01:57 Because let me back up a step here so i can put false.

02:05 Because copper is going to be more stable with a full d shell than with a full s shell.

02:16 There.

02:17 So what i mean by that is it is only going to have 4s1.

02:20 It's going to take one of those s electrons to fill up that d shell because a filled d shell is more stable than that partially filled d shell that we had.

02:34 And it's so much more stable that it ends up being more stable if it takes one of those electrons from the 4s.

02:40 All right.

02:41 So that's an exception to the filling rules because it's more stable with that d filled.

02:46 So that one is false.

02:48 The third, the third the third one wants to know number of valence electrons.

02:53 And that third statement is true, because the valence electrons are those in the highest energy level.

03:00 So what we see here is kr, and then we see 5s2, 4d10, 5p5.

03:14 So this is going to be a halogen.

03:17 And if we're looking for the electrons in the highest energy level, that's going to be the fifth energy level...

Question

Please give Ace some feedback