The half-life of Plutonium−239, t1/2 is 2.41 × 10⁴<span> yrs
time taken to reach tolerable level = seven half-lives
= 7 x t1/2
= 7 x </span>2.41 × 10⁴ yrs
= 168700 yrs
= 1.687 x 10⁵ yrs
Hence, the period of time that <span>Plutonium-239 must be stored is </span>1.687 x 10⁵ years.
Answer: 4 HCl (g) + O₂ (g) → 2 Cl₂ (g) + 2 H₂O (l)
Explanation:
4 moles of hydrogen chloride (note that it is in the gaseous phase, otherwise it would be hydrochloric acid) react with 1 mole of oxygen gas to form 2 moles of chlorine gas and 2 moles of liquid water.
To conform with the law of conservation of mass, the equation must be balanced, this means that there must be the same number of each type of atom on both sides of the arrow.