The tirst ionization energies (in kJ/mol) for the elements in the 3rd row of the periodic table (PT) are shown below: Element + First + Na 496 Mg 738 Al 577 Si 786 1,060 1,000 CI 1,256 Ar 1,520 • What best explains why the ionization energies generally increase as you go across the periodic table? • What best explains why the ionization energy of Mg is greater than that of Al?

MISSED THIS? Read Section 9.7 (Page). Consider the following set of successive ionization energies: IE₁ 578 kJ/mol IE2 = 1, 820 kJ/mol IE3 = 2, 750 kJ/mol IE4 11,600 kJ/mol = = Part A To which third-period element do these ionization values belong? Express your answer as an element symbol. Submit Request Answer

Arrange strontium, cesium, iodine, and lead in order of increasing atomic size using general periodic table trends.     Cs < Sr < Pb < I     I < Sr < Pb < Cs     Sr < Cs < I < Pb     Sr < I < Cs < Pb

a) Which element is least likely to lose an electron? Choose one: He, Be, Na, Mg, Ca, Sr,  b) Why is the element you selected the least reactive?

For each element determine the charge of the ion that will most likely form based on the data? What do you look for? Why does this happen? Based on the data, locate the family/column number for each element on the periodic table.

Using the data in the tables and Coulomb's law, calculate the energy change for this reaction (per formula unit of CaS). Ca(g) + S(g) → CaS(g) Ionization energy Atom Mg Ca Electron affinity Atom O S Ionic radius Ion Mg²+ Ca²+ 0²- S²2- I₁ (aJ) 1.23 0.980 EA₁ (aJ) -0.234 -0.332 I₂ (aJ) 2.41 1.90 EA₂ (aJ) +1.30 +0.980 Radius (pm) 72 100. 140. 184 ▲Erxn = 6.76 Incorrect aJ

Since the first ionization energy of rubidium is +403 kJ mol, how many kJ of energy is it required to convert 22.90 g gaseous rubidium to +1 monoatomic ion at constant temperature?

79

Two sets of ionizations are shown in the tables below. Complete the tables by ordering each set of ionizations by increasing amount of energy required. In other words, for each set choose "1" next to the ionization that would require the least energy, "2" next to the ionization that would require the next least energy, and so on. S-> S+ + e- Ca-> Ca+ + e- He-> He+ + e- --------------- K-> K+ + e- Fr-> Fr+ + e- Si-> Si+ + e-

element X has an electron affinity of 295.3 kJ/mol and the following ionization energies (in kJ/mol): IE1 = 1.008e3, IE2 = 1.846e3, IE3 = 3.20e3. In what column of the periodic table is this element probably found?