why is it being less sure about the placement of electrons in an atom is actually an improvement over earlier models?

Idon’t understand this page, can someone ?

Which statement is true about the part of the electromagnetic spectrum that human eyes can detect? it contains only the colors of the rainbow and television waves. o it is divided into seven ranges of wavelengths. it contains ultraviolet, visible, and infrared light. it is divided into nine ranges of wavelengths.

Agas in a balloon at constant pressure has a volume of 160 ml at -125*c. what is its volume at 29.0*c?