How reactive is an atom of sodium(na) and why? question 1 options: sodium (na) is not very reactive because it does not have a full valence shell. sodium (na) is very reactive because it does not have a full valence shell. sodium (na) is very reactive because it does not have enough protons in the nucleus. sodium (na) is not very reactive because it can only bond with chlorine (cl) to become salt. i need this asap !

Why is there friction between objects

Starting with only the balmer series light (visible light), how could we ensure that the solar panels generate a current that mark can use for his power station? a)by gradually increasing the brightness (amount) of light that we shine on it. b)by gradually increasing the frequency of the light we shine on it. c)by gradually increasing the wavelength of the light that we shine on it.

As you are trying to move a heavy box of mass m, you realize that it is too heavy for you to lift by yourself. there is no one around to , so you attach an ideal pulley to the box and a massless rope to the ceiling, which you wrap around the pulley. you pull up on the rope to lift the box. use g for the magnitude of the acceleration due to gravity and neglect friction forces. once you have pulled hard enough to start the box moving upward, what is the magnitude f of the upward force you must apply to the rope to start raising the box with constant velocity? express the magnitude of the force in terms of m, the mass of the box.