Which factor is responsible for the red color of mars?
sulphur dioxide
methane
iron oxide
nitrogen

The best answer is iron oxide.

Also known as the red planet, the red color of Mars is die to that its regolith (surface material) contains high amount of iron oxide, which is the same compound that renders blood and rust red.

The iron oxide in Mars is thought to have formed long ago. The rusty material was spread around the planet in the huge dust storms that are so characteristic of the this planet.

The red color caused the Greeks of ancient times to give it the name of their god of war.

relative dating involves things like higher layers are most recent than rocks lower in the sequence. this can be extended to the known sequence of fossils. rocks containing rabbit fossils are later than those containing dinosaur fossils.  

absolute dating methods mainly use radioactive elements that have known rates of decay and produce recognizable products. for example potassium 40 decays to produce argon. once a rock has solidified the argon is trapped. by measuring the argon and potassium0 you can get an accurate number for the age.  

some other methods are good for archaeological ages. dendrochronology involves recognizing the sequence of tree rings. the orientation of magnetized particles in baked clay can be used to date a fire.

hope this .. .