Ca2+ would bond to any element in a 1 to 1 ratio that had an equal and opposite charge.
Neon is a noble gas, and doesn’t form bonds m
Carbon isn’t typically found in ion state, but if it did, it would likely by C4+
Flouring in ionic state is F1-, so you would need 2 flourines to cancel the 2+ charge of Calcium
Then the only option left would be Oxygen which, when in ion form is found be 2-
The residue of coal decomposition in the manufacture of steel is coal tar. It is a by product of the coking process in the blast furnace. Coal gas is another by product but is not the answer becuase this is not a residue which is a solid. Coal gas is a gas. Coke in fact is one of the reactants fed for steel making. Answer is choice 3.
First calculate the electric charge used to deposit 1.0 g Pt
C = (1.0 g Pt) (1 mol Pt / 195.1 g Pt) ( 2 mol e / 1 mol Pt)
( 96485 C / 1 mol e)
C = 989.08 C
C = It
Where I is the current
T is the time
T = C / i
T = 989.08 C / 0.15 A
T = 6593.88 s
T = 1.83 hrs