Plz solve like you would write it down tysm guys

The volume of helium in a blimp is 6.28 x 10^9 millimeters. the density of helium in the blimp is .1786 kilogram/meter^3. find the mass of the helium in the blimp.

In the reaction h2co3 (aq) + 3nh3 (aq) = 2 nh4+ (aq) + co3 2-, how many electrons are transferred?

Which is true about metals used for jewelry, such as platinum and gold? a. they have low flammability. b. they have low reactivity. c. they have high flammability. d. they have high reactivity.