If u pour flour and sugar in one bowl is the substance a mixture atom or element

In 2002, the rare earth elements mine in mountain pass, california was closed because

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?

What is the empirical formula of a compound that is 50.7% antimony and 49.3% selenium ?