Plants can grow from sunlight and water.
Na = 23 x 2.40 = 55.2
O = 16 x 2.40 = 38.4
H = 1 x 2.40 = 2.40
55.2 + 38.4 + 2.4 = 96
2.40 mol of NaOH = 96 amu
An element cannot be broken down any further. Elements can be found on the periodic table
Answer : The half life of 28-Mg in hours is, 6.94
Explanation :
First we have to calculate the rate constant.
Expression for rate law for first order kinetics is given by:
![k=\frac{2.303}{t}\log\frac{a}{a-x}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt%7D%5Clog%5Cfrac%7Ba%7D%7Ba-x%7D)
where,
k = rate constant
t = time passed by the sample = 48.0 hr
a = initial amount of the reactant disintegrate = 53500
a - x = amount left after decay process disintegrate = 53500 - 10980 = 42520
Now put all the given values in above equation, we get
![k=\frac{2.303}{48.0}\log\frac{53500}{42520}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7B48.0%7D%5Clog%5Cfrac%7B53500%7D%7B42520%7D)
![k=9.98\times 10^{-2}hr^{-1}](https://tex.z-dn.net/?f=k%3D9.98%5Ctimes%2010%5E%7B-2%7Dhr%5E%7B-1%7D)
Now we have to calculate the half-life.
![k=\frac{0.693}{t_{1/2}}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B0.693%7D%7Bt_%7B1%2F2%7D%7D)
![9.98\times 10^{-2}=\frac{0.693}{t_{1/2}}](https://tex.z-dn.net/?f=9.98%5Ctimes%2010%5E%7B-2%7D%3D%5Cfrac%7B0.693%7D%7Bt_%7B1%2F2%7D%7D)
![t_{1/2}=6.94hr](https://tex.z-dn.net/?f=t_%7B1%2F2%7D%3D6.94hr)
Therefore, the half life of 28-Mg in hours is, 6.94