What type of star has an absolute brightness of 5 and a surface temperature around 3,000 °c?

a supergiant
b giant
c main sequence
d dwarf

Answer : The correct answer is option A : Supergiants

Explanation :

In the above graph absolute brightness is marked on y-axis and surface temperature is marked on x-axis.

To find out what type of star has an absolute brightness of 5 and a surface temperature around 3,000 °C, we will draw a straight line from x axis which represents a temperature of 3,000 °C and another straight line from y-axis which represents absolute brightness of 5.

From the attached graph we can see that these 2 lines meet in the region shown by Supergiants

Therefore we can say that, Supergiants has an absolute brightness of 5 and a surface temperature around 3,000 °C

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.