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

select one:
a. supergiant
b. giant
c. main sequence
d. dwarf

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

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.