Information you will need: Uranium-238 to Lead-206 - half-life 4.5 billion years
Uranium-235 to Lead-207 – half-life 713 million years
Carbon-14 to Nitrogen – 14 – half-life 5730 years
1) A zircon crystal from a lava flow was examined for geologic age. The
scientists measured the 235U, and 207Pb, and determined that 25% of
the atoms were 235U, and 75% were 207Pb.
b) What is the absolute age of the Lava flow?

answer: i don't know

explanation:

you need to provide a picture, otherwise i can't tell you.

if you can provide one, i'd be more than happy to you with this!

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.

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)