# Question 7.PS.11: Atomic Radii and Periodic Trends Using only a periodic table......

Using only a periodic table, list these atoms in order of decreasing size: Br, Cl, Ge, K, S.

Step-by-Step
The 'Blue Check Mark' means that this solution was answered by an expert.

K > Ge > Br > S > Cl

Strategy and Explanation Based on the periodic trends in atomic size, we expect the radius of Cl to be smaller than that of Br, which is below it in Group 7A; S in Period 3 should be smaller than Br, which is in Period 4. Because size decreases across a period, we expect Cl to be smaller than S. Of the Period 4 atoms, Ge is earlier in the period than Br and therefore larger than it, but smaller than K, which starts the period. From these trends we can summarize the relative sizes of the radii, from largest to smallest, as K > Ge > Br > S > Cl.

Question: 7.PS.13

## Ionization Energies Using only a periodic table, arrange these atoms in order of increasing first ionization energy: Al, Ar, Cl, Na, K, Si. ...

K < Na < Al < Si < Cl < Ar Strategy...
Question: 7.PS.12

## Trends in Ionic Sizes For each of these pairs, choose the smaller atom or ion: (a) A Cu atom or a Cu^2+ ion (b) A Se atom or a Se^2- ion (c) A Cu^+ ion or a Cu^2+ ion ...

(a) $Cu^{2+}$ ion           (b) [late...
Question: 7.PS.10

## Electron Configurations for Transition Elements and Ions (a) Write the electron configuration for the Co atom using the noble gas notation. Then draw the orbital box diagram for the electrons beyond the preceding noble gas configuration. (b) Cobalt commonly exists as 2+ and 3+ ions. How does the ...

(a) [Ar]3d^74s^2; [Ar]    \boxed{↑↓}\quad\b...
Question: 7.PS.9

## Atoms and Their Ions Complete this table. ...

Strategy and Explanation A neutral Se atom has the...
Question: 7.PS.8

## Valence Electrons (a) Using the noble gas notation, write the electron configuration for bromine. Identify its core and valence electrons. (b) Write the Lewis dot symbol for bromine ...

(a) $[Ar] 3d^{10}4s^24p^5$      Core ...
Question: 7.PS.7

## Electron Configurations Using only Figure 7.16 and the periodic table as a guide, give the complete electron configuration, orbital box diagram, and noble gas notation for vanadium, V. ...

$1s^22s^22p^63s^23p^63d^34s^2$ [late...
Question: 7.PS.6

## Quantum Numbers, Subshells, and Atomic Orbitals Consider the n = 4 principal energy level. (a) Without referring to Table 7.3, predict the number of subshells in this level. (b) Identify each of the subshells by its number and letter designation (as in 1s) and give its l values. (c) Use the ...

(a) Four subshells (b) 4s, 4p, 4d, and  4f;...
Question: 7.PS.5

## Tennis Balls and Electrons At Wimbledon, tennis serves routinely reach more than 100 mi/h. Compare the de Broglie wavelength (nm) of an electron moving at a velocity of 5.0 × 10^6  m/s with that of a tennis ball traveling at 56.0 m/s (125 mi/h). Masses: electron = 9.11 × 10^-31  kg; tennis ball ...

The wavelength of the electron is much longer than...
Question: 7.PS.4

## Electron Transitions (a) Calculate the frequency and wavelength (nm) corresponding to the n = 2 to n = 5 transition in a hydrogen atom. (b) In what region of the electromagnetic spectrum does this transition occur? ...

(a) 6.906 × 10^{14}  s^{-1} ; 434.1  nm[/la...
Question: 7.PS.3