Question

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

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 first ionization energy (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:

• Ionization Energy Trends:
• Across a Period: Ionization energy generally increases from left to right across a period. This is because as you move from left to right, the atomic number increases, the number of protons in the nucleus increases, and the electrons are more strongly attracted to the nucleus. So, it becomes more difficult to remove an electron (higher ionization energy).
• Down a Group: Ionization energy generally decreases down a group. As you go down a group, the number of electron shells increases. The outermost electrons are farther from the nucleus and are shielded by the inner - shell electrons. So, they are easier to remove (lower ionization energy).
• For the first four questions (circle the element with the largest first ionization energy):
• 1. Iron (Fe) vs Germanium (Ge): Ge is to the right of Fe in the periodic table. Using the across - a - period trend, Ge has a higher first ionization energy.
• 2. Rubidium (Rb) vs Chlorine (Cl): Cl is on the right side of the periodic table (halogen group), while Rb is on the left (alkali metal group). Cl has a much higher first ionization energy.
• 3. Fluorine (F) vs Astatine (At): F is at the top of the halogen group, and At is at the bottom. Using the down - a - group trend, F has a higher first ionization energy.
• 4. Helium (He) vs Radon (Rn): He is at the top of the noble gas group, and Rn is at the bottom. He has a higher first ionization energy.
• For questions 5 - 11 (order in increasing first ionization energy):
• 5. Hydrogen (H), Lithium (Li), Beryllium (Be):
• Li is an alkali metal (lower ionization energy). H has a 1s¹ configuration. Be has a 2s² configuration. As we move from Li (left - most) to Be (right - most) in the second period (and H is in the first period but has a relatively simple electron configuration), the order is \(Li\lt H\lt Be\).
• 6. Boron (B), Iodine (I), Indium (In):
• In is in a lower period (higher atomic number, more shells) than B and I. B is in the second period, and I is in the fifth period but is a halogen. Using the trends, \(In\lt B\lt I\).
• 7. Strontium (Sr), Gold (Au), Tin (Sn):
• Sr is an alkaline earth metal (lower ionization energy). Sn is a post - transition metal. Au is a transition metal. Using the periodic trends, \(Sr\lt Sn\lt Au\).
• 8. Seaborgium (Sg), Magnesium (Mg), Palladium (Pd):
• Sg is a synthetic element in a lower period (higher shells). Mg is an alkaline earth metal. Pd is a transition metal. The order is \(Sg\lt Mg\lt Pd\).
• 9. Krypton (Kr), Sodium (Na), Oxygen (O):
• Na is an alkali metal (lowest ionization energy). O is in the second period (higher than Na but lower than Kr which is a noble gas). The order is \(Na\lt O\lt Kr\).
• 10. Carbon (C), Cobalt (Co), Titanium (Ti):
• Ti is a transition metal. Co is also a transition metal. C is a non - metal in the second period. Using the periodic trends, \(Ti\lt Co\lt C\).
• 11. Neon (Ne), Rutherfordium (Rf), Selenium (Se):
• Rf is a synthetic element in a lower period (higher shells). Se is a non - metal. Ne is a noble gas. The order is \(Rf\lt Se\lt Ne\).

Answer:

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