Answer:
2.95 g / mL
Explanation:
For this problem, we will simply use the equation that density is equivalent to mass over volume. We are given the mass of the object and the initial and final volumes of water in the cylinder. Thus we can find the density as such:
Density = Mass / ( Final Volume - Initial Volume )
Density = 3.689 g / ( 8.54 mL - 7.29 mL )
Density = 3.689 g / ( 1.25 mL )
Density = 2.9512 g / mL
Hence, the density of the object is 2.9512 g / mL.
Cheers.
Answer:
32,0 days.
Explanation:
The radioactive decay follows:

Where Nt is the concentration in a time t (6,22x10¹⁷), N₀ is the initial concentration (9,95x10¹⁸) Half life time is 8,0 days and t is the time it take to drop this concentration. Replacing:






It take <em>32,0 days</em>
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I hope it helps!
An endothermic reaction is when the energy is absorbed, while an exothermic reaction releases energy.