Digital ACT Science Practice Question #1779

Based on Table 9, as atomic number (Z) increases across Period 3 from left to right, atomic radius: Experiment Context (Period 3 Elemental Properties): Physical chemists analyzed five consecutive elements across Period 3 of the periodic table: Table 9: - Sodium (Na, Z=11): Atomic radius = 186 pm; Electronegativity = 0.93; 1st Ionization Energy = 496 kJ/mol - Magnesium (Mg, Z=12): Atomic radius = 160 pm; Electronegativity = 1.31; 1st Ionization Energy = 738 kJ/mol - Silicon (Si, Z=14): Atomic radius = 118 pm; Electronegativity = 1.90; 1st Ionization Energy = 786 kJ/mol - Phosphorus (P, Z=15): Atomic radius = 110 pm; Electronegativity = 2.19; 1st Ionization Energy = 1012 kJ/mol - Chlorine (Cl, Z=17): Atomic radius = 99 pm; Electronegativity = 3.16; 1st Ionization Energy = 1251 kJ/mol