How many electrons are in the nucleus of an atom with an atomic number of 7?!!

Aphysical reaction is a process in which one or more reactants change into one or more products with different properties. select the best answer from the choices provided t f

How many grams of n2h4 will be consumed by 23 g of n2o4

Plz choose one of the compounds from the table and explain how you know the numbers of atoms in your formula. is it possible for two different compounds to be made from the exact same two elements? why or why not? with a limited number of elements (less than 120 are known), does this mean we also have a small number of compounds or do we have a large number of compounds in this world?