Answer:
<em>249 kJ</em>
Explanation:
To obtain the energy change of the reaction:
H₂O → H₂ + ¹/₂ O₂
It is necessary to obtain the difference between bond energy of the products and bond energy of the reactant, thus:
Energy of products:
1 mol of H-H bond × 436 kJ/mol = 436 kJ
¹/₂ mol of O=O bond × 498 kJ/mol = 249 kJ
Energy of reactant:
2 mol of H-O bond × 467 kJ/mol = 934 kJ
Energy change of the reaction is:
934 kJ - (436 kJ + 249 kJ) = <em>249 kJ</em>
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I hope it helps!
Answer:
protons and neutrons
Explanation:
The nucleus of the atom contains protons and neutrons. The electrons of the atom orbit the nucleus.
The carbon will make two double bonds with the oxygen: O=C=O this way carbon will make 4 covalent bonds and oxygen will make 2 covalent bonds
The answer is D because the each energy level contains a different numbers
The number of valence electron in sodium is 1 and that in chlorine are 7. In order to complete the octet (8 electrons in outermost shell) sodium can give its valence electron to an atom with more electronegativity. Here, chlorine is more electronegative than sodium, due to 7 valence electrons it required one more electron to complete its octet.
Therefore, chlorine can take 1 valence electron of sodium to form ionic bond. In the ionic compound so formed, both sodium and chlorine have complete octets. In aqueous solution they exist as
and
ions, the positive charge on sodium indicates that it donates its one electron and negative charge on chlorine indicates that it accepts an electron.
All this happen due to difference in electronegativity of sodium and chlorine (chlorine is more electronegative than sodium).