Selenium (Se) the most common isotope of this element. The nucleus consists of 34 protons (red) and 46 neutrons (blue).
Answer:
The simulated 1H NMR spectrum for ethyl acetate is shown in the drawing attached.
Explanation:
To construct this NMR it is necessary to identify the essential components that can produce resonance peaks.
Two main groups can be identified, the acetyl group containing a sub-component (CH3) capable of producing a resonance peak, and the ethyl group containing two components (CH2 and CH3) each of which can produce on its own its own resonance peak.
Answer: The child isotope has an atomic mass of 206.
Explanation:
Alpha decay : When a larger nuclei decays into smaller nuclei by releasing alpha particle. In this process, the mass number and atomic number is reduced by 4 and 2 units respectively.
General representation of an element is given as: 
where,
Z represents Atomic number
A represents Mass number
X represents the symbol of an element
General representation of alpha decay :


There are several information's already given in the question. Based on those information's the answer can be easily determined.
M = <span>1.11 g CH4
C = </span>4.319 kJ g C⋅°
∆T = 35.65 - 24.85 degree centigrade
= 10.8 degree centigrade.
Then
∆H =−M ⋅ C ⋅∆T
= - 1.11 * 4.319 * 10.8
= - 51.776 kJ/<span>mol
I hope the procedure is clear enough for you to understand.</span>