Answer:

Explanation:
Given that:
Half life = 30 min
Where, k is rate constant
So,
The rate constant, k = 0.0231 min⁻¹
Using integrated rate law for first order kinetics as:
Where,
is the concentration at time t
is the initial concentration
Given that:
The rate constant, k = 0.0231 min⁻¹
Initial concentration
= 7.50 mg
Final concentration
= 0.25 mg
Time = ?
Applying in the above equation, we get that:-

Fluorine 20 (F - Atomic number 9 and atomic mass 20). Firstly we need to know what is beta decay. Beta decay occurs when one neutron changes into a proton and an electron therefore the atomic mass will remain the same as even though we loose a neutron it is replaced by a proton, the atomic number is always raised by 1 when one beta decay occurs. The produced electron is shot out of the nucleus at an incredible speed. This speedy electron we call a beta particle.
Ok now the reaction.
20 20 0
F -> Ne + e
9 10 -1
Remember the atomic number determines the nature of the element ( i.e what elemnt it is).
Hope this helps :).
There are six liquids found on the periodic table.
1. Bromine
2. Mercury
3. Caesium
4. Gallium
5. Rubidium
6. Francium
There should be mass balance and the charge balance between the reactants and the products
Mass balance : total no of individual atoms of each type should be balanced before and after the reaction
Charge balance : Overall charge of the reactants should be balanced with the overall charge of the products
You can balance,
1)by just looking at it
2)by Algebraic method given above or
3)by the redox method
You need to know how to get the oxidation numbers in order to use the oxidation method
Explanation:
As the total concentration is given as 1.2 mM. And, it is also given that salt present in the solution is NaCl.
As sodium chloride is an ionic compound so, when it is added to water then it will dissociate into sodium and chlorine ions as follows.

So, it means in total there will be formation of 2 ions when one molecules of NaCl dissociates.
Therefore, concentration of chlorine ions will be calculated as follows.
Concentration of
ions =
= 0.6 mM
Thus, we can conclude that the concentration of chloride ions is 0.6 mM.