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Unit 1 Radiometric Dating
Comprehension Note (Portfolio)
1. 글의 분야 : Archeology 2. 주제 (Topic) : Radiometric dating
3. 요지 (Main Idea)
Radiometric dating has two types - carbon dating and uranium-lead dating.
4. 세부 내용 및 사건 (Further Details)
1st – radiometric dating : to establish accurate dates for various pieces of evidence
2nd –how to : by measuring measures the ratio of isotopes
3rd - Carbon dating : dead organisms,
the ratio between carbon-14 and carbon-12 changes
4th – Problem : the ratio in the atmosphere fluctuates, susceptible to contamination,
not applied to over 50,000 years
5th – Uranium-lead dating : sample over billions of year old,
highly accurate by considering two different uranium isotopes
6th – Problem : not applied to organic materials,
only in certain specialized circumstances. damage to a sample
5. 요약 (Summary)
Radiometric dating is to know accurate dates for various pieces of evidence by
measuring measures the ratio of isotopes. There are two types of radiometric dating.
Carbon dating can be used for dead organisms by calculating the ratio between
carbon-14 and carbon-12 changes. With the fluctuating ratio in the atmosphere, this
type is susceptible to contamination and limited to organisms below 50,000 years.
Uranium-lead dating, the other type, can be used for samples over billions of year old
and highly accurate by considering two different uranium isotopes. But, it is only used
to inorganic materials only in certain specialized circumstances. Sometimes, it can
damage to a sample, causing inaccurate results.
6. 어휘 정리 (Vocabulary) ④
① ⑤
② ⑥
③
7. 구문 학습 (Structure)
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Comprehension Note (Portfolio)
1. 글의 분야 : Archeology 2. 주제 (Topic) : Radiometric dating
3. 요지 (Main Idea)
Radiometric dating has two types - carbon dating and uranium-lead dating.
4. 세부 내용 및 사건 (Further Details)
1st – radiometric dating : to establish accurate dates for various pieces of evidence
2nd –how to : by measuring measures the ratio of isotopes
3rd - Carbon dating : dead organisms,
the ratio between carbon-14 and carbon-12 changes
4th – Problem : the ratio in the atmosphere fluctuates, susceptible to contamination,
not applied to over 50,000 years
5th – Uranium-lead dating : sample over billions of year old,
highly accurate by considering two different uranium isotopes
6th – Problem : not applied to organic materials,
only in certain specialized circumstances. damage to a sample
5. 요약 (Summary)
Radiometric dating is to know accurate dates for various pieces of evidence by
measuring measures the ratio of isotopes. There are two types of radiometric dating.
Carbon dating can be used for dead organisms by calculating the ratio between
carbon-14 and carbon-12 changes. With the fluctuating ratio in the atmosphere, this
type is susceptible to contamination and limited to organisms below 50,000 years.
Uranium-lead dating, the other type, can be used for samples over billions of year old
and highly accurate by considering two different uranium isotopes. But, it is only used
to inorganic materials only in certain specialized circumstances. Sometimes, it can
damage to a sample, causing inaccurate results.
6. 어휘 정리 (Vocabulary) ④
① ⑤
② ⑥
③
7. 구문 학습 (Structure)
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