Can you post the question
I think its c because solid,liquid nor plasma really fits to the description and i don't really know the last one so the best option is probably C.
Answer:
An atom is composed of them
Explanation:
The coefficient in a chemical formula represents the amount of each chemical present. The amount of a substance is measured in moles.
According to the law of conservation of mass, the amount of BARIUM present of the reactants is the same as the amount present in the products (the precipitate).
(11.21 g BaSO4) / (233.4 g/mol BaSO4) = 0.0480 mol BaSO4 and original barium salt
(10.0 g) / (0.0480 mol) = 208.3 g/mol
So it must have been BaCl2, because the molar mass of Barium is 137 which leave 71 grams left. Since Barium is a +2 charge, it means the atom next to it must be twice. Chlorine mass is 35, which twice is 71
