Question

ap chemistry
name: shyja shant id: w076 chemistry u3l13 02 ct module day 2 hw
note: annotate all questions & diagrams! cross out part of the answer choices that may makes the answer incorrect.
directions: each set of lettered choices below refers to the numbered statements immediately following it. select the one lettered choice that best fits each statement. a choice may be used once, more than once, or not at all in each set.
(a) cs
(b) pb
(c) br
(d) se

1. has the highest electronegativity

(a) cs
(b) pb
(c) br
(d) se
** 2. has the largest atomic radius
(a) cs
(b) pb
(c) br
(d) se
** 3. has the lowest first - ionization energy
(a) cs
(b) pb
(c) br
(d) se

1. which of the following properties generally decreases across the periodic table from sodium to chlorine?

(a) first ionization energy
(b) atomic mass
(c) electronegativity
(d) atomic radius
** 5.
ionization energies for element x (kj mol⁻¹)
first: 580
second: 1,815
third: 2,740
fourth: 11,600
fifth: 14,800
the ionization energies for element x are listed in the table above. on the basis of the data, element x is most likely to be
(a) mg
(b) al
(c) si
(d) p
ap chemistry page 1 of 4

Explanation:

1. Electronegativity increases across a period and decreases down a group. Cl is in period 3, group 17—higher than Br (group17, period4), Se (group16, period4), Pb (group14, period6).
2. Atomic radius increases down a group and decreases across a period. Cs is in period6, group1—larger than Pb (period6, group14), Br (period4, group17), Se (period4, group16).
3. First ionization energy decreases down a group and increases across a period. Cs (period6, group1) has lower energy than Pb (period6, group14), Br (period4, group17), Se (period4, group16).
4. Across period3 (Na to Cl), atomic radius decreases as nuclear charge increases, pulling electrons closer. First ionization energy and electronegativity increase; atomic mass increases.
5. A large jump in ionization energy occurs when removing an electron from a full inner shell. The jump between 3rd (2740) and 4th (11600) IE means 3 valence electrons—Al has 3 valence electrons.

Answer:

1. A. Cl
2. A. Cs
3. A. Cs
4. D. Atomic radius
5. B. Al