Which of these describes an endothermic reaction? a) energy is relesed by the reaction b) energy is absorbed by the reaction c) no energy is transferred by the reaction d) energy is created in the reaction {plz answer asap! }

Bohr's model could only explain the spectra of which type of atoms? single atoms with one electron single atoms with more than one electron bonded atoms with one electron bonded atoms with more than one electron

What substance has a mass of 9.5g and volume of 2.1cm^3

How does a sample of helium at 15 degree celsius compare to a sample of helium at 215 k? a) the helium at 15 degrees celsius has a higher average kinetic energy that the sample at 215 k. b) the helium at 15 degrees celsius has lower nuclear energy that the sample at 215 k. c) the helium at 15 degrees celsius has slower- moving atoms that the sample at 215 k. d) the helium at 15 degrees celsius has smaller atoms than the sample at 215 k.