A geologist is comparing the properties of different minerals. He rubs each one on a piece of white tile and observes the color of the powder that is left behind. What type of test did he perform?

              Streak test is used to compare the properties of different minerals.  

Explanation:

                    Streak test is perform on rocks to check the properties of a mineral or rocks. If you have a piece of white floor tile, You can use it for the test. In this test we rub mineral on a piece of white tile Turn your tile so that the dull side faces up. Take your rocks one at a time and rub them back and forth over the surface of the tile and observe the color of the powder left behind which will tell about the type of mineral.

answer: andy garner, a 17-year-old who decided to become a human guinea pig in 1965 and go without sleep for 11 days. by the second day his eyes had already stopped focusing, and he lost the ability to identify objects by touch. by day three he was moody and uncoordinated and by the end he had trouble with short term memory and had even started hallucinating.

and a rare genetic mutation called fatal familial insomnia, where people can’t sleep at all, gets progressively worse over months or years and leads to dementia and death.

a devoted soccer fan died after staying awake 48 hours to watch the world cup, she said. ‘while his untimely death was due to a stroke, studies show chronically sleeping fewer than six hours a night increases stroke risk by 4 1/2 times compared with those getting a consistent seven to eight hours.'

*shorten it up as your wish*

(i have divided it into 3 simple paragraphs)