Answer:<span>d. 145 minutes
</span>
Half-life is the time needed for a radioactive to decay half of its weight. The formula to find the half-life would be:
Nt= N0 (1/2)^ t/h
Nt= the final mass
N0= the initial mass
t= time passed
h= half-life
If 25.0% of the compound decomposes that means the final mass would be 75% of initial mass. Then the half-live for the compound would be:
Nt= N0 (1/2)^ t/h
75%= 100% * (1/2)^ (60min/h)
3/4= 1/2^(60min/h)
log2 3/4 = log2 1/2^(60min/h)
0.41503749928 = -60min/h
h= -60 min / 0.41503749928= 144.6min
Answer:
a. A reaction in which the entropy of the system increases can be spontaneous only if it is endothermic.
Explanation:
The change in free energy (ΔG) that is, the <u>energy available to do work</u>, of a system for a constant-temperature process is:
-
When ΔG < 0 the reaction is spontaneous in the forward direction.
- When ΔG > 0 the reaction is nonspontaneous. The reaction is
spontaneous in the opposite direction.
- When ΔG = 0 the system is at equilibrium.
If <u>both ΔH and ΔS are positive</u>, then ΔG will be negative only when the TΔS term is greater in magnitude than ΔH. This condition is met when T is large.
I'd say no because the only pure substances are elements
Answer:
Human body systems can be compared to anything that has many parts doing specialized jobs to help the whole. Here's an example: The human body is like a city. The nervous system of the body is like the government of the city because the nervous system controls the body like the government controls the city.
If the egg is fertilized by a man's sperm, the resulting embryo would travel down the fallopian tube and implant in the uterus. This happens around the 20th day of the menstrual cycle. ... Around day 26 of your cycle, the uterus will begin the process to shed its lining causing menstruation to begin
hope this helps
