Which statement defines activation energy?
it is the sum of the maximum energy and reactant energy.
it is the sum of the product energy and reactant energy.
it is the difference between reactant energy and maximum energy.
it is the difference between product energy and reactant energy.

Why does the sun appear to be the brightest star in the sky? a- its apparent brightness is much greater than other stars. b- it burns more gas, making it brighter than any other star. c- it is the largest star in the galaxy, so it is the brightest star. d- its relative distance to earth is closer than the other stars.

The blackbody curve for a star name zeta is shown below. what is the peak wavelength for this star ?

Classify this reaction: 2al+n2-> aln.