注目の話題: どっちの妻がいい？; 女性の友達ってどうやって作れば良いですか？; 独身、恋愛経験なし。これから何を目標に生きたらいいか？

Let's enjoy English!

No.263　12/12/12 20:37
燻し銀三 ( 50代 ♂ Oe38xe ) あ+あ-

【Measurement of an era with the half-value period 半減期】

《A half-value period of C14》

The C14 is radioactive isotope 放射性同位体 of carbon.The number of 14 means its mass.As to an indication of the mass,we usually put its number at the upper left of the chemical element,but I can't express it with this cepllphone,so please understand it.😃　　　　　　　　　　　
By the way, let's suppose we discovered a wooden sculpture which seemed to done hundreds of yearsa ago.😱

It's the isotope of the carbon,C14 of which we make use.The isotope emits beta ray,and changes into N14,isotope of nitrogen.A half-value period of C14 is no less than 5370 years.

《Photosynthesis 光合成 and its suspension》

Vegetation does photosynthesis as long as it's alive,absorbs carbon dioxide from the air and water from the ground.The vegetation produces sugar content 糖分,making use of an energy of sunlight.😃

Carbon is a mixture of the isotope,so it includes the C14 to some extent.As for ratio of the C14,the carbon dioxide includes same amount.😃