C14 is often used to tell the age of formerly living things.C14 has a half-life of about 6000 years.Now,a cave is discovered with the remains of burned wood from a fire.The wood was found to be approximately 42000 years old.What percent of the origin

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C14 is often used to tell the age of formerly living things.C14 has a half-life of about 6000 years.Now,a cave is discovered with the remains of burned wood from a fire.The wood was found to be approximately 42000 years old.What percent of the origin

C14 is often used to tell the age of formerly living things.C14 has a half-life of about 6000 years.Now,a cave is discovered with the remains of burned wood from a fire.The wood was found to be approximately 42000 years old.What percent of the origin
C14 is often used to tell the age of formerly living things.C14 has a half-life of about 6000 years.Now,a cave is discovered with the remains of burned wood from a fire.The wood was found to be approximately 42000 years old.What percent of the original radioactive C14 remains in the charred wood?
谷歌翻译出来：C14经常被用来告诉岁以前生活的东西.C14的半衰期约6000年.现在,一个山洞里发现的遗骸从火中烧木头的.这种木材被发现是约42000年大的.多少百分比保持在原来的放射性C14烧焦的木头?

C14 is often used to tell the age of formerly living things.C14 has a half-life of about 6000 years.Now,a cave is discovered with the remains of burned wood from a fire.The wood was found to be approximately 42000 years old.What percent of the origin
m=M(1/2)^(t/T)
　　其中M为反应前原子核质量,m为反应后原子核质量,t为反应时间,T为半衰期.
t/T=7
带入m/M=0.78125%

42000年是7个半衰期。剩余的物质可以写成（1/2）^n n表示半衰期的个数。
根据半衰期公式，（1/2）^7=1/128=0.78%

C14同位素通常用来告诉我们历史久远的生物的年龄。C14的半衰期约为6000年。现在，在一个山洞里面发现了一些燃烧过后留下的木材。这些木材大约有42000年的历史。请问有多少百分比的C14仍留在这些木材里面呢？

半衰期为6000 经过42000年后 一共经过了7个半衰期 由于这个是公比为0.5的等比数列

所以这些木材C14同位素还剩下(1/2)^7 =78%...

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C14同位素通常用来告诉我们历史久远的生物的年龄。C14的半衰期约为6000年。现在，在一个山洞里面发现了一些燃烧过后留下的木材。这些木材大约有42000年的历史。请问有多少百分比的C14仍留在这些木材里面呢？

半衰期为6000 经过42000年后 一共经过了7个半衰期 由于这个是公比为0.5的等比数列

所以这些木材C14同位素还剩下(1/2)^7 =78%

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