A laser beam has a wavelength of 500nm and the power of the laser beam is 2.8W. The number of emitted photons by this laser during time t is 3.6×10^18 photons. Calculate the time t. (1W = 1 J/s)

Answer    "a salt" would be the best answerexplanationsalts can be defined as ionic compounds that are neither acids nor bases. nacl is an example of a salt, and its ionic.an enzyme is an organic compound which is covalently bonded, not ionically bonded.acids are generally held together by covalent bondsan element does not need any bonds to exist

Answer/when the cell uses energy;

Melting increases as mass increases. since alkanes are not branched molecular structures, the one with the heavier mass will have higher melting point.  octane's mp > butane's mp

Is there a c and d?