Since f is positive I would say f
Answer:
A- Group 1/1A
Explanation:
In group 1A they are all highly reactive metals, which tarnish when exposed to air.
The solution for this problem would be:
H + ions from pH = 4.0 x 10^-4 moles.
But H2SO4 gives off 2 moles of H+ ions / mole.
Moles of H2SO4 = 2.0 x 10^-4
Mass = 2 x 10^-4 moles x 98 = 1.96 x 10^-3 grams
1.96 x 10^-3 grams / 10^3 = 1.96 x 10^-6 Kg.