It takes 16.02 days for the activity of Y90
<h3>Further explanation
</h3>
The atomic nucleus can experience decay into 2 particles or more due to the instability of its atomic nucleus.
Usually radioactive elements have an unstable atomic nucleus.
The main particles are emitted by radioactive elements so that they generally decay are alpha (α), beta (β) and gamma (γ) particles
General formulas used in decay:
T = duration of decay
t 1/2 = half-life
N₀ = the number of initial radioactive atoms
Nt = the number of radioactive atoms left after decaying during T time
No=192 μCi
Nt=3 μCi
t1/2=2.67 days
Cookies, they are more than a compound
3asy
Answer:
3
Explanation:
They have thick fur with has helped them to live in those areas HAVE A NICE DAY ;]
A) i believe the reaction is exothermic, because 27.6 kg of thermal energy is gained by the water solution, the dissolution of urea is exothermic. Exothermic reaction is a chemical reaction that releases energy by light or heat. It is the opposite of an endothermic reaction where heat is gained by the reaction.
b) The water gained the heat released when urea dissolve. That is the water gained 27.6 kJ, while dissolution of urea released 27.6 kJ. Therefore, the heat gained is equal to the heat lost.
c) From part B, since heat gained is equal to heal lost, then
250 g × (Tf -30) ×4.18 J/g = 27600 J
= 1045 Tf - 31350J = 27600 J
Tf = 56.41°C.
Therefore the final temperature of the solution is 56.41°C
d) The initial and final temperature in Fahrenheit
°F = °C × (9/5) +32,
Thus, 30°C will be equal to 86° F
while 56.41 will be equivalent to 133.54 ° F
