You are an archaeologist who has just found an ancient fire ring containing charcoal fragments. you send these fragments to the lab for carbon-14 analysis. the report you receive from the lab states that these fragments have 25% of the amount of carbon-14 compared to modern wood. using 5730 years as the half-life of carbon-14, you conclude that these charcoal fragments are about years old. can you explain how you get an answer of 11460? you!

Thus we can conclude that these charcoal fragments are about 11460 years old.

Explanation:

a) for completion of half life:  

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

Expression for rate law for first order kinetics is given by:

where,

k = rate constant  

t = age of sample

a = let initial amount of the reactant  = 100

a - x = amount left after decay process = 25

b) for completion of 75 % of reaction  

Thus we can conclude that these charcoal fragments are about 11460 years old.

what have scientists found to be the most efficient and effective way to insert new sequences into an individual? a-scientists have created genetically altered foods that release dna during digestion. b-scientists use viruses to insert specific gene sequences. c-scientists irradiate genes so that they can be absorbed through the skin.

americans began to notice growing differences between the northern and southern sections of the country. there were more people living in cities in the north, which made it more urban. more people lived on farms in the south, which made it more rural. while many people were farmers in the northern states, there were now other ways to make a living, such as working in mechanical cotton gins factories manufacturing cloth, tools and other goods. people in the north supported high tariffs on goods imported from europe because the extra cost encouraged people to “buy american” instead. in the southern states, planters did not like tariffs because they sold most of their production to europe and bought their tools from there as well. southerners believed the protective tariff was something that only northern factory owners keep their profits high. so the southern politicians came up with an idea. they would opt out. they would simply ignore the protective tariff. it was ‘null and void’ in south carolina. the state would not collect the taxes on goods imported into south carolina, no matter what the president said they had to do. this decision led to the nullification crisis.