Why do elements in a vertical column of the periodic table have similar chemical properties? They have the same number of electrons
They have the same number of protons.
They have the same number of outer electrons.
They have equal numbers of protons and electrons.

There is a single path for electrons. the current decreases when additional resistors are added. the current will be the same in each resistor. these statements best describe a(n) circuit.

  the mississippians were considered to be  horticulturalists, which means they were

Ammonium perchlorate nh4clo4 is the solid rocket fuel used by the u.s. space shuttle. it reacts with itself to produce nitrogen gas n2 , chlorine gas cl2 , oxygen gas o2 , water h2o , and a great deal of energy. what mass of nitrogen gas is produced by the reaction of 2.1g of ammonium perchlorate?