Answer:
a) 
b) 
c) 
Explanation:
The symbols of the isotopes are written like

where,
X is the element
A is the mass number (protons + neutrons)
Z is the atomic number (protons)
<em>a) Iodine-131</em>
The atomic number of iodine is 53. The mass number of this isotope is 131. The symbol is
.
<em>b) Iridium-192</em>
The atomic number of iridium is 77. The mass number of this isotope is 192. The symbol is
.
<em>c) Samarium-153</em>
The atomic number of samarium is 62. The mass number of this isotope is 153. The symbol is
.
Larynx connects the pharynx to the trachea and is also part of the respiratory system
About 6.5x10^22 molecules.
(5g C2H5OH)x(1 mol C2H5OH/46g C2H5OH)x(6.02x10^23 molecules C2H5OH/1 mol C2H5OH)=(3.01E24)/46=6.5x10^22.
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Diffusion is a process that results from the random motion of molecules and results in a net movement of matter from a high-concentration region to a low-concentration zone.