Answer:
= 72900 years
Explanation:
- The half-life is the time taken by a radioactive material to decay by half the original amount.
- The half-life of plutonium-239 is 24300 years which means it takes 24300 years to decay by half the original amount.
To calculate the time taken for a mass of 8 kg to decay to 1 kg we use;
New mass = Original mass x (1/2) ^n, where n is the number of half-lives
Therefore;
1 kg = 8 kg × (1/2)^n
1/8 = (1/2)^n
solving for n;
n =3
Therefore;
Time = 3 × 24300 years
= 72900 years
It will, therefore, take 72900 years for 8 kg of plutonium-239 to decay to 1 kg.
Answer:
Electromagnetic Force
Explanation:
Every aspect of chemical reaction is the output of electromagnetic force though the forces can take on many forms because of the quantum wave nature of particles.
The electromagnetic force has the ability to attract opposite charges such as protons and electrons and it repels same charges such as electrons and protons.
This force is an important force in the chemical reaction as it it is responsible for bonding between atoms. Though other forces are unique in their own way but they don't affect chemical reaction. Force of gravity is not strong enough to affect chemical reactions; when nuclear forces are involved in a reaction, such reaction is a nuclear reactor; not chemical reaction.
One of the roles of the electromagnetic force in chemical reaction is that it holds the electrons that are in the outer orbit around the nucleus; this, in the long run creates bonds with other chemical elements to create a visible matter.
Answer:
The reactant/reagent that would be most atom economical is EtI (Ethy Iodide) and KOH (potassium oxide) as base
This is because the iodo group are weak base hence they have a good leaving character (i.e they are unstable on their own ) which would increase the rate of reaction and the strong base KOH give the most atom economical
Explanation:
The original concentration of the acid solution is 6.175 
10^-4 mol / L.
<u>Explanation:</u>
Concentration is the ratio of solute in a solution to either solvent or total solution. It is expressed in terms of mass per unit volume
HBr + NaOH -----> NaBr + H2O
There is a 1:1 equivalence with acid and base.
Moles of NaOH = 72.90 10^-3 0.25
= 0.0182 mol.
[ HBr ] = moles of base / volume of a solution
= 0.0182 / 29.47
= 6.175 10^-4 mol / L.
CO2 is the emperical formula of carbon dioxide
