Answer:
False. Chemical changes are always physical changes
Answer: sorry can't help ya
Explanation:
Sorry it's just I don't really know how to answer this question myself wish you the best of luck ;3
Answer:
k = 6.31 x 10⁻³ min⁻¹
Explanation:
The equation required to solve this question is:
k = 0693 / t half-life
This equation is derived from the the equation from the radioctive first order reactions:
ln At/A₀ = -kt
where At is the number of isoopes after a time t , and A₀ is the number of of isotopes initially. The half-life is when the number of isotopes has decayed by a half, so
ln(1/2) = -kt half-life
-0.693 = - k t half-life
t half-life = 109.8 min
⇒ k = 0.693 / t half-life = 0.693 / 109.8 min = 6.31 x 10⁻³ min⁻¹
