Answer:
The amount left after 49.2 years is 3mg.
Explanation:
Given data:
Half life of tritium = 12.3 years
Total mass pf tritium = 48.0 mg
Mass remain after 49.2 years = ?
Solution:
First of all we will calculate the number of half lives.
Number of half lives = T elapsed/ half life
Number of half lives = 49.2 years /12.3 years
Number of half lives = 4
Now we will calculate the amount left after 49.2 years.
At time zero 48.0 mg
At first half life = 48.0mg/2 = 24 mg
At second half life = 24mg/2 = 12 mg
At 3rd half life = 12 mg/2 = 6 mg
At 4th half life = 6mg/2 = 3mg
The amount left after 49.2 years is 3mg.
To measure length scientists may use rulers, meter sticks, etc. and to measure mass they may use a balance.
Answer:
N₂ + 3H₂ → 2NH₃ ΔH = - 92.2KJ
Explanation:
Let's write out the chemical equation between Nitrogen and Hydrogen to Form Ammonia.
Nitrogen + Hydrogen = Ammonia
N₂ + H₂ → NH₃
A Thermochemical Equation is a balanced stoichiometric chemical equation that includes the enthalpy change, ΔH.
The balanced stoichiometric chemical equation is given as;
N₂ + 3H₂ → 2NH₃
92.2 kJ of energy are evolved for each mole of N2(g) that reacts. And from the equation, 1 mole of N2 reacts.
The enthalpy change, ΔH = - 92.2KJ. The negative sign is because heat is being evolved.
The balanced thermochemical equation;
N₂ + 3H₂ → 2NH₃ ΔH = - 92.2KJ
Answer:
The word radon is derived from radium, of which radon is gas. Early in its discovery it was also called radium emanation and niton, which comes from the Latin nitens, Since 1923, however, it has been called radon.
