Oxygen because it is one the table of elements and none of the others are.
Answer:
1) fractional distillation
3) centrifugation
3x10^8 / (670.8 * 10^-9) =4.47x10^14 Hz 4.47x10^14 Hz multiplied by plank's constant = 2.9634x10^-19
2.96 x10-19 J
Group 2 contains soft, silver metals that are less metallic in character than group 1 elements. There is a fairly strong conductivity trend within each row, left to right, and a weaker trend top to bottom. The elements in group 2 are moderately good conductors, while the elements on the right are very poor conductors. <span>As you move vertically between rows, conductivity decreases overall, but slowly.
Group 2 have a generally low electronegativity. Electronegativity decreases moving left and down across the table.</span>
