How many electrons belong to a neutral atom with an atomic mass of 36 amu?

How many moles of al3+ ions are in 1.25 moles of al2o3

Consider the story you just read. all but one of the choices below indicate that something is living.

The activation energy for the reaction no2(g)+co2(g)⟶no(g)+co(g) is ea = 300 kj/mol and the change in enthalpy for the reaction is δh = -100 kj/mol . what is the activation energy for the reverse reaction?