Select all the answers that apply. Types of evidence that astronomers use to estimate the age of the universe and stars include .

movement of galaxies
molecular clocks
fossil evidence
chemical composition of the Sun
radioactive dating of rocks

The answer that apply;

Movement of galaxies

Chemical composition of the Sun.

Light and the time it takes to traverse between particular points in the universe is used to calculate the age of distant stars and galaxies. Because of the vast nature of the universe, light takes earth years for it to travel from one galaxy to another. By knowing the speed of light and the amount of time taken for the light to travel from a distant celestial body, and use of geometric calculations, and brightness measurements we can tell in approximation the age of the celestial body. The age can also star can also be determined by their composition. Youg stars are mainly found have lighter elements such as helium. As they age, they have more composition of heavier elements such as iron. This is due to the fusion at the core of the sun that fuses lighter elements to heavier elements.

The answers that apply are;

radiometric dating of rocks

fossil evidence

gradual processes of rock

Radiometric dating means the use of half-life of naturally decaying elements such as carbon-14 to tell the age of a fossil or rock. The gradual formation of rocks such as lithification of sedimentary rock or metamorphosis of rock is also used to calculate the age of the earth by studying the stage in the process in which the rocks are in and extrapolating the age using calculations.

Explanation:

2b2t

explanation:

2b2t

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.