B. Don't take up most of the space in an atom,
Answer:
m = 671 grams
Explanation:
Given that,
No of moles, n = 4.9
Molar mass of Barium, M = 137 g
Mass divided by molar mass is equal to no of moles. It can be given by the formula as follows :

or
m = 671 grams
So, the total mass of the sample of Barium is 671 grams.
He improved and followed from the works of Luigi Galvani, which used a 'frog galvanoscope' as a prototype of measuring current. He recognized that a compass could actually measure current, given that it is placed near coil of wire.
Assuming that 2H2O(l) is the product, the reactants would be 2H2(g) and O2(g). The number of moles in the reactants would be 2 moles of H2 and 1 mole of O2.
Well it's definitely an alkaline solution.