Why aren't iron, cobalt and iron in the same group of elements?

Anybody wanna ? (picture included? )

If the force applied to an object remains constant, is more power needed for the object to move faster ? explain

The vapour pressure of benzene is 53.3 kpa at 60.6 °c, but it fell to 51.5 kpa when 19.0 g of a non-volatile organic compound was dissolved in 500 g of benzene. calculate the molar mass of the compound.