The name is Potassium bromide.
<h2>Total distance divided by total elapsed time gives : Average speed </h2>
Explanation:
Speed
It is the distance traveled by body with respect to time .
Its formula is Speed = distance /time
V=S/T
units : m/sec or Km/hr
Distance
It is total path traveled by body in any direction .
It unit and symbol is : S and unit = m /Km
Average speed
It is the total distance traveled by body with respect to total time taken to travel that given distance .
Average speed = total distance /total time
A.s = T.D/T.T
unit = m/sec or Km/hr
Instantaneous velocity
It is the distance traveled by body at particular instant of time ,in given direction .
Displacement
It is the shortest path traveled by body in given direction .
I am sure the answer is D
Consider this balanced chemical equation:
2 H2 + O2 → 2 H2O
We interpret this as “two molecules of hydrogen react with one molecule of oxygen to make two molecules of water.” The chemical equation is balanced as long as the coefficients are in the ratio 2:1:2. For instance, this chemical equation is also balanced:
100 H2 + 50 O2 → 100 H2O
This equation is not conventional—because convention says that we use the lowest ratio of coefficients—but it is balanced. So is this chemical equation:
5,000 H2 + 2,500 O2 → 5,000 H2O
Again, this is not conventional, but it is still balanced. Suppose we use a much larger number:
12.044 × 1023 H2 + 6.022 × 1023 O2 → 12.044 × 1023 H2O
These coefficients are also in the ratio of 2:1:2. But these numbers are related to the number of things in a mole: the first and last numbers are two times Avogadro’s number, while the second number is Avogadro’s number. That means that the first and last numbers represent 2 mol, while the middle number is just 1 mol. Well, why not just use the number of moles in balancing the chemical equation?
2 H2 + O2 → 2 H2O
B. 11,540
<h3>Further explanation
</h3>
The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually radioactive elements have an unstable atomic nucleus.
General formulas used in decay:

T = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
Nt=25 g
No=100 g
t1/2=5770 years
