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 .
Answer:
To gain stability
Explanation:
If the outermost shell is not completely filled with electrons, the element has one of the three options: gaining electrons, losing electrons or sharing electrons. By gaining or losing electrons, ionic compounds are produced. Sharing of electrons results in the formation of covalent compounds.
<span>Use the Ideal law Equation :
P.V= n.R.T
V = 0.5 L
P = 1.0 atm
</span><span>R= 0.0821 L*atm/mol*K
</span>
<span>n = R*T/P*V
</span><span>P*V= n*R*T
</span>
1.0 * 0.5 = n *<span>0.0821*298
0,5 = n* 24.4658
n = 0,5 / 24.4658
n =0.0204 moles
</span>