Answer:
0.1gmin-1
Explanation:
mass = 0.5g
time = 5minutes
rate= mass/time = 0.1gmin-1
Answer:
r² x h
Explanation:
A can is cylindrical in nature. Using the formula of the volume of the can, we can find this unknown volume.
The volume of cylinder is given as:
Volume of a cylinder = Area x height
Volume of a cylinder =
r² x h
Therefore density of the can;
Density = 
Answer:
Hydrogen(H) and Heluim(He)
Explanation:
These are the only two valennce electrons and 1 energy levels.
Chemical equation represents a redox reaction :
2Li + MgCl₂ → 2LiCl + Mg
<h3>Further explanation</h3>
The oxidation-reduction reaction or abbreviated as Redox is a chemical reaction in which there is a change in oxidation number
Reaction
2Li + MgCl₂ → 2LiCl + Mg
Oxidation is an increase in oxidation number, while reduction is a decrease in oxidation number.
Oxidation

Reduction

The radioactive decay obeys first order kinetics
the rate law expression for radioactive decay is
![ln\frac{[A_{0}]}{[A_{t}]}=kt](https://tex.z-dn.net/?f=ln%5Cfrac%7B%5BA_%7B0%7D%5D%7D%7B%5BA_%7Bt%7D%5D%7D%3Dkt)
Where
A0 = initial concentration
At = concentration after time "t"
t = time
k = rate constant
For first order reaction the relation between rate constant and half life is:

Let us calculate k
k = 0.693 / 72 = 0.009625 years⁻¹
Given
At = 0.25 A0

time = 144 years
So after 144 years the sample contains 25% parent isotope and 75% daughter isotopes**
Simply two half lives