Question

periodic trends - electronegativity practice
for each of the following grouping of elements, circle the element with the largest electronegativity

1. iron (fe), germanium (ge)
2. rubidium (rb), chlorine (cl)
3. fluorine (f), astatine (at)
4. helium (he), radon (rn)

for each of the following groupings of elements, order them in order of increasing electronegativity (smallest to largest)

1. hydrogen (h), lithium (li), beryllium (be)
2. boron (b), iodine (i), indium (in)
3. strontium (sr), gold (au), tin (sn)
4. seaborgium (sg), magnesium (mg), palladium (pd)
5. krypton (kr), sodium (na), oxygen (o)
6. carbon (c), cobalt (co), titanium (ti)
7. neon (ne), rutherfordium (rf), selenium (se)

Explanation:

Step1: Recall the trend of electronegativity

Electronegativity increases across a period from left to right and decreases down a group. Noble gases (except for some heavier noble gases in certain contexts) generally have very low electronegativity as they have a full valence shell and little tendency to gain electrons.

Step2: Analyze each group

Group 1: Iron (Fe), Germanium (Ge)

Fe is a metal in the d - block. Ge is a metalloid. As we move from left to right in the periodic table (Fe is in group 8, period 4; Ge is in group 14, period 4), electronegativity increases. So Ge has a higher electronegativity than Fe.

Group 2: Rubidium (Rb), Chlorine (Cl)

Rb is a group 1 (alkali metal) element, very electropositive (low electronegativity). Cl is a group 17 (halogen) element. Halogens have high electronegativity. So Cl has a higher electronegativity than Rb.

Group 3: Fluorine (F), Astatine (At)

F is in period 2, group 17; At is in period 6, group 17. Since electronegativity decreases down a group, F has a higher electronegativity than At.

Group 4: Helium (He), Radon (Rn)

He is a noble gas in period 1; Rn is a noble gas in period 6. Noble gases have low electronegativity, and as we move down the group, the electronegativity (for noble gases that can show some reactivity trends) slightly increases (but still very low compared to non - noble gas non - metals). But in general, He has a more stable electron configuration and even less tendency to gain electrons than Rn (in the context of these two), so Rn has a slightly higher electronegativity (but both are very low).

Group 5: Hydrogen (H), Lithium (Li), Beryllium (Be)

H is in period 1, group 1; Li is in period 2, group 1; Be is in period 2, group 2. As we move from left to right across a period (Li to Be) and H has an electronegativity value of 2.2, Li has 0.98, Be has 1.57. So the order is Li < H < Be.

Group 6: Boron (B), Iodine (I), Indium (In)

B is in period 2, group 13; In is in period 5, group 13; I is in period 5, group 17. B has an electronegativity of 2.04, In has 1.78, I has 2.66. So the order is In < B < I.

Group 7: Strontium (Sr), Gold (Au), Tin (Sn)

Sr is in period 5, group 2; Sn is in period 5, group 14; Au is in period 6, group 11. Sr has an electronegativity of 0.95, Sn has 1.96, Au has 2.54. So the order is Sr < Sn < Au.

Group 8: Seaborgium (Sg), Magnesium (Mg), Palladium (Pd)

Sg is a synthetic element (period 7, group 6); Mg is in period 3, group 2; Pd is in period 5, group 10. Mg has an electronegativity of 1.31, Pd has 2.20. Sg (based on periodic trends, as a transition metal in a lower period) would have a relatively low electronegativity. So the order is Sg < Mg < Pd.

Group 9: Krypton (Kr), Sodium (Na), Oxygen (O)

Kr is a noble gas (period 4, group 18); Na is in period 3, group 1; O is in period 2, group 16. Na has an electronegativity of 0.93, Kr has a very low electronegativity (approx 0.82 in some Pauling - like scales for noble gases considering some bonding trends), O has 3.44. So the order is Na < Kr < O.

Group 10: Carbon (C), Cobalt (Co), Titanium (Ti)

C is in period 2, group 14; Ti is in period 4, group 4; Co is in period 4, group 9. C has an electronegativity of 2.55, Ti has 1.54, Co has 1.88. So the order is Ti < Co < C.

Group 11: Neon (Ne), Rutherfordium (Rf), Selenium (Se)

Ne is a noble gas (period 2, group 18); Rf is a synthetic element (period 7, group 4); Se is in period 4, group 16. Ne has a very low electronegativity (approx 0.0 in the Pauling scale as it doesn't form many compounds in the traditional sense), Rf (as a transition metal in a lower period) has a low electronegativity. Se has an electronegativity of 2.55. So the order is Ne < Rf < Se.

Answer:

1. Ge
2. Cl
3. F
4. Rn
5. Li < H < Be
6. In < B < I
7. Sr < Sn < Au
8. Sg < Mg < Pd
9. Na < Kr < O
10. Ti < Co < C
11. Ne < Rf < Se