Which one of the following is a combustion reaction? a. ch4 + 2 o2 co2 + 2 h2o b. hbr + naoh nabr + h2o c. xe (aq) + h2o(l) hxe(aq) + oh- (aq) d. nacl (aq) + agno3 (aq) nano3 (aq) + agcl (s)

Needthe meter is the standard unit for: 1) height 2) length 3) weight 4) mass

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.

Click the button that shows the correct relationship of the electron affinities of the elements sodium and phosphorus. sodium’s electron affinity value is more negative than the electron affinity value of phosphorus. phosphorus’ electron affinity value is more negative than the electron affinity value of sodium. this information cannot be determined using the periodic table. answer is b on e2020.