Answer :
121.5 <span>
μCi
Explanation : We have Ce-141 half life given as 32.5 days so if the activity is 3.8 </span><span>μci after 162.5 days of time elapsed we have to find the initial activity.
We can use this formula;
</span>

3.8 /

=

((0.693 X 162.5 ) / 32.5) = 121.5
<span>
On solving we get, The initial activity as 121.5 </span>μci
Answer : The formula unit of Sr & Cl is
and the formula unit of Al & S is 
Explanation :
Formula unit : it is defined as the lowest number ratio of ions of an elements in an ionic compound or covalent compound.
For the formula unit of Sr & Cl, two chloride ions
are needed to neutralize the one strontium ion
.
For the formula unit of Al & S, three sulfide ions
are needed to neutralize the two aluminium ion
.
The formula unit of
and
are shown below.
Some chemical heat highly temperature it was produce poison gas
Answer:
1. K<10−3
Explanation:
Equilibrium Constant is an expression which involves the concentration of the product divided by the concentration of the reactant molecules.
However the concentration of the pure liquid and pure solid is regarded as 1.
Equilibrium expression for the equation 2H2(g)+O2(g)⇌2H2O(g)
Equilibrium Constant = [H2O]^2/[H2]^2 x [O2]
Since H2O is a pure liquid, its concentration = 1
There fore;
Equilibrium Constant = 1/[H2]^2 x [O2]
This shows that the Equilibrium Constant of the equation will be less than 1 and greater than 0.