The answer is B.
A cannot be the answer is melting is a physical change. No chemical reaction took place.
B is the answer as it is a EXOTHERMIC REACTION so heat will be given off.
C cannot be the answer as dissolving is basically atoms becoming ions, not a chemical reaction whereby a reactant reacts with another reactant to form a product.
D cannot be the answer. Same reason as for why A is not the answer.
Cheers.
C.
Explanation: Because mirrors are lighter, and they are easier than lenses to make perfectly smooth.
There is no <span>radioactive decay</span>
Answer:
19.6 kg*m/s^2 = 19.6 N
Explanation:
Weight is mass times acceleration due to gravity. And hopefully you know that acceleration due to gravity on earth is 9.8 m/s^2 So what is half of that? 4.9. So now the calculation is super simple.
mass = 4 kg and acceleration = 4.9 m/s^2 so now we multiply these two numbers and get 19.6 kg*m/s^2. kg*m/s^2 is also known as Newtons, abbreviated with an N so the final result is 19.6 N.
