Cellular respiration can be thought of as the opposite of photosynthesis. In cellular respiration oxygen is turned into carbon dioxide while in photosynthesis carbon dioxide is tuned to oxygen.
I hope this helps. let me know in the comments if anything is unclear.
Spectroscopy because it talks about the study of spectrum of light.
Physical change .. you cannot undo chemical ... physical is like bending , shattering a mirror , denting something ..
chemical would be rust or something .
Answer:
Photosynthesis
Explanation:
Carbon cycle involves the exchange of components between the hydrosphere, biosphere and atmosphere. During carbon cycle, materials such as gases, minerals which are necessary for life are interchange. For example, animals pass out faeces on the soil which is rich in urea. Urea decomposes to provide nitrogen into the soil through bioactive bacterials. The nitrogen is used up by plants to grow. During photosynthesis, plants uses carbon dioxide and water to produce glucose and release oxygen for animals to use. It's like a purification system where one waste product from one organism is used by the other to survive.
Equation of photosynthesis
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
Answer:
0.9715 Fraction of Pu-239 will be remain after 1000 years.
Explanation:
Where:
= decay constant
=concentration left after time t
= Half life of the sample
Half life of Pu-239 = 
[
![\lambda =\frac{0.693}{24,000 y}=2.8875\times 10^{-5} y^{-1]](https://tex.z-dn.net/?f=%5Clambda%20%3D%5Cfrac%7B0.693%7D%7B24%2C000%20y%7D%3D2.8875%5Ctimes%2010%5E%7B-5%7D%20y%5E%7B-1%5D)
Let us say amount present of Pu-239 today = 
A = ?
![A=x\times e^{-2.8875\times 10^{-5} y^{-1]\times 1000 y}](https://tex.z-dn.net/?f=A%3Dx%5Ctimes%20e%5E%7B-2.8875%5Ctimes%2010%5E%7B-5%7D%20y%5E%7B-1%5D%5Ctimes%201000%20y%7D)
0.9715 Fraction of Pu-239 will be remain after 1000 years.
