A 73.0 g sample of an unknown compound contains 12.9 g of hydrogen. What is the percent by mass of hydrogen in the compound?

In what environment would mineral formation caused by high pressures and high temperatures most likely occur?

Precision can be defined as the o exact center of a data set. o reproducibility of a measured value. o correlation between two variables that are measured in a data set agreement between a measured value and an accepted value.

What is the enthalpy of combustion (per mole) of c4h10 (g)? –2,657.5 kj/mol –5315.0 kj/mol –509.7 kj/mol –254.8 kj/mol