<span>Answer: D. They all have the same number of electrons in the electron cloud</span>
Answer:carbon-14 levels in the atmosphere
Explanation:
When carrying out radiocarbon dating, the level of carbon-14 in a sample is compared with the level of carbon 14 in the atmosphere because, objects exchange carbon-14 with the atmosphere.
Comparison of the activities of carbon-14 in the atmosphere and in the sample gives the age of the sample since the half-life of carbon-14 is a constant.
Absolutely nothing a neutron has a neutral charge
Answer:
-1190.24 kJ
Explanation:
The enthalpy change in a chemical reaction that produces or consumes gases is given by the expression:
ΔH = ΔU + Δngas RT
where Δn gas is the change of moles of gas, R is the gas constant,and T is temperature.
Now from the given balanced chemical reaction, the change in number of mol gas is equal to:
Δn gas = mole gas products - mole gas reactants = 2 - 5/2 = -1/2 mol
Sionce we know ΔU and the temperature (298 K), we are in position to calculate the change in enthalpy.
ΔH = -1189 x 10³ J + (-0.5 mol ) 8.314 J/Kmol x 298 K
ΔH = -1.190 x 10⁶ J = -1.190 x 10⁶ J x 1 kJ/1000 J = -1.190 x 10³ J
Reduction Reaction:
Ag⁺ + 1e⁻ → Ag ------ (1)
Oxidation Reaction:
NO₂⁻ → NO₃⁻ + 2e⁻
Balance Oxygen atoms, by adding H₂O to side having less number of O atoms, and H⁺ to side having greater number of O atoms.
NO₂⁻ + H₂O → NO₃⁻ + H⁺ + 2e⁻
Balance the H⁺'s,
NO₂⁻ + H₂O → NO₃⁻ + 2 H⁺ + 2e⁻ ------ (2)
Multiply eq. 1 by 2 to balance the number of electrons in overall reaction.
2 Ag⁺ + 2e⁻ → 2 Ag ----- (3)
Compare eq. 2 and 3,
NO₂⁻ + H₂O → NO₃⁻ + 2 H⁺ + 2e⁻
2 Ag⁺ + 2e⁻ → 2 Ag
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NO₂⁻ + H₂O + 2 Ag⁺ → NO₃⁻ + 2 Ag + 2 H⁺
