Correlate the biggest jump in ionization energy to the number of valence electrons in each atom

Asystematic approach to problem solving is called a (an)

Ain is , is 's of ? 0.62 0.79 1.27 1.50

According to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does maria's voyage take according to samir?