Answer:
Fluorine
Explanation:
Fluorine has 9 total electrons. The first two are in the 1s level, and the remaining electrons are on the outer level of the atom, with 2 in the s level and 5 in the p level. The electron configuration is 1s2 2s2 2p5.
Explanation:
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Answer:
Question: A patient is diagnosed with a damage in the thyroid gland.
Which isotope is used to treat the patient?
Option:
A. Copper-64
B. Cobalt-60
C. Carbon-14
D. Iodine-131
Correct answer : D. Iodine-131
Question: Give the definition of isotopes.
Answer : Isotopes is the atoms of elements with the same proton number but different number of neutrons.
The balanced chemical reaction for the complete combustion of C4H10 is shown below:
C4H10 + (3/2)O2 --> 4CO2 + 5H2O
The enthalpy of formation are listed below:
C4H10: -2876.9 kJ/mol
O2: none (because it is pure substance)
CO2: -393.5 kJ/mol
H2O: -285.8 kJ/mol
The enthalpy of combustion is computed by subtracting the total enthalpy formation of the reactants from that of the products.
ΔHc = (4)(-393.5 kJ/mol) + (5)(-285.8 kJ/mol) - (-2876.9 kJ/mol)
= -<em>126.1 kJ</em>
Thus, the enthalpy of combustion of the carbon is -126.1 kJ.
