Because burning is a non-reversible chemical change.
Answer:
this may be wrong but I am not sure
To resolve these forces we have to make use of the sines and cosines.
To resolve this force in 30 degree north of west, the answer will be
100*sin(30)
The answer will be 50N
Now to resolve the force acting 60 degree north of east
100* cos(60)
The answer will be 50N.
This also adds to the total force acting that is 50+50=100N. This is the way forces are resolved according to their specified angles.
Honestly, I am quite confused with what Nv stands for because there is no element with that symbol. However, I still get the concept of finding the average molecular mass of an element. Let's just assume that nv stands for a specific type of element and it has two isotopes: nv-293 and nv-295. Isotopes have the same number of protons but differ in mass number (protons+neutrons).
To find the average atomic weight, just multiply the individual weights with the respective composition of the isotope. Since there are only two isotopes, they constitute 50% each. So, the average atomic weight is
(50%)(293.15 amu) + (50%)(<span>295.30 amu) = 294.225 amu
Hence, the atomic weight of nv is 294.225 atomic mass units.</span>