Answer:
Copper is a metal made up of copper atoms closely packed together. As a result, the electrons can move freely through the metal. For this reason, they are known as free electrons. They are also known as conduction electrons because they help copper be a good conductor of heat and electricity.
Explanation:
The best description of Ernest Rutherford's experiment is letter C. The positively charged particles were fired through a gold foil. Most of these particles went right through, while others bounced back. This experiment led to the discovery of the nucleus.
Answer:
The cycling of matter is important to many Earth processes and to the survival of organisms the existing matter must cycle continuously for this planet to support life Water, carbon, nitrogen, phosphorus, and even rocks move through cycles If these materials did not cycle, Earth could not support life.
Explanation:
Sulfide would be an AWNSER but
Answer: The half-life of a first-order reaction is, 
Explanation:
All the radioactive reactions follows first order kinetics.
Rate law expression for first order kinetics is given by the equation:
![k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7B%5BA_o%5D%7D%7B%5BA%5D%7D)
where,
k = rate constant = ?
t = time taken = 440 s
![[A_o]](https://tex.z-dn.net/?f=%5BA_o%5D)
= initial amount of the reactant = 0.50 M
[A] = left amount = 0.20 M
Putting values in above equation, we get:
The equation used to calculate half life for first order kinetics:
Putting values in this equation, we get:
Therefore, the half-life of a first-order reaction is,
