What does the sum of the protons and neutrons in an atom equal

If 34.2 grams of lithium react with excess water, how many liters of hydrogen gas can be produced at 299 kelvin and 1.21 atmospheres? 2 li (s) + 2 h2o (l) yields 2 lioh (aq) + h2 (g)

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

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.