The number of molecules decrease
The heat released by the substance in the calorimeter is equal to the heat absorbed by water which results to the decrease and increase in temperature, respectively.
We use m Cp ΔT to balance the heat involved
(m Cp ΔT) subs in calorimeter = <span>(m Cp ΔT) water
</span>125 g * Cp * (97.0-23.5 ) C = 250 g *(4.18 J/C g)* (23.5-20)
Cp = 0.398 J/Cg
Answer is B
It will take 5.2 years to decay.
The half life of cobalt-60 is 5.2 years. The half life is the time taken for the mass of the substance to decrease by a half.
here, the amount of remaining substance is 50%,
so, 
n. log (0.5) = log (0.5)
n = 1
So it would take 1 half lives to decay this much, which is 1 x 5.2 which is 5.2 years.
what do you mean by radioactive decay ?
The process through which an unstable atomic nucleus loses energy via radiation is known as radioactive decay, also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration. A material that has unstable nuclei is considered as radioactive.
Learn more about decay here:-
brainly.com/question/13853996
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Answer:
3 NH4OH (l) + H3PO4 (aq) → (NH4)3PO4 (aq) + 3 H2O (l)
Explanation:
This is an acid-base reaction (neutralization): NH4OH is a base, H3PO4 is an acid
Cyclic nucleotides cAMP and cGMP are part of almost all major cellular signaling pathways. Phosphodiesterases (PDEs) are enzymes that regulate the intracellular levels of cAMP and cGMP. Protein kinase A or cAMP-dependent protein kinase mediates most cAMP effects in the cell. Over the last 25 years, various components of this group of molecules have been involved in human diseases, both genetic and acquired. Lately, the PDEs attract more attention. The pharmacological exploitation of the PDE’s ability to regulate cGMP and cAMP, and through them, a variety of signaling pathways, has led to a number of new drugs for diverse applications from the treatment of erectile dysfunction to heart failure, asthma, and chronic obstructive pulmonary disease. We present the abstracts (available online) and selected articles from the proceedings of a meeting that took place at the National Institutes of Health (NIH), Bethesda, MD, June 8–10, 2011.
