Why was there no increase in the reaction rate with 8 g of substrate as compared to 4 g of substrate?

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.

Match the mixture with the substance// i really need on this guys (it’s a pic btw)

How are isotopes of the same chemical element alike? how are they different?