Which statement best describes balancing equations and the law of conservation of mass? There are more atoms in the reactants than in the products, and the total mass is the same in the reactants and in the
products
The number of atoms is the same in the reactants and in the products, and the total mass is the same in the reactants and
in the products
There are fewer atoms in the reactants than in the products, and the total mass is less in the reactants than in the
products
There are more atoms in the reactants than in the products, and the total mass is higher in the reactants than in the
products

What happens to energy in an open system?

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)

Two nitro no2 groups are chemically bonded to a patch of surface. they can't move to another location on the surface, but they can rotate (see sketch at right). it turns out that the amount of rotational kinetic energy each no2 group can have is required to be a multiple of ε, where =ε×1.010−24 j. in other words, each no2 group could have ε of rotational kinetic energy, or 2ε, or 3ε, and so forth — but it cannot have just any old amount of rotational kinetic energy. suppose the total rotational kinetic energy in this system is initially known to be 32ε. then, some heat is removed from the system, and the total rotational kinetic energy falls to 18ε. calculate the change in entropy. round your answer to 3 significant digits, and be sure it has the correct unit symbol.