Answer asap! will give brainliest!
while testing the air bags in a car, engineers observed that the compressed air in the bags expanded on impact. which of the following best justifies the type of changes taking place during the process?

1. physical change because heat of combustion is a chemical property.
2. chemical change because heat of combustion is a chemical property.
3. physical change because compressibility is a physical property.
4.chemical change because compressibility is a physical property.

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.

We are hoping to create 5.72 grams of glucose. the plant was given 4.75 liters of co2 and 2.81 g of h20. which reactant was the limiting reagent? how much excess mass did we have of the other reactant?

How many joules of heat are required to raise thetemperature of 750 g of water from 11.0 °c to 19.0 °c?