which of the following steps in the formation of KCI releases energy?

A.K{solid} -> K{gas}
B.K {GAS} -> K+ {GAS} + e-
C.C1 {GAS} -> C1- {GAS}
D.C1 {GAS} + e- -> C1 - {GAS}
E. K+ {GAS} + C1- {GAS} -> KC1 {SOILD}
A. A
B. C
C. B AND A
D. D AND E

I will be happy to critique your thinking on this.

To determine which steps in the formation of KCI release energy, we need to review the formation process and identify any reactions where energy is released.

The formation of KCI (potassium chloride) involves combining potassium (K) and chlorine (CI) atoms to form K+ and Cl- ions, which then combine to form the salt KCI.

Let's analyze each step:

A. K(solid) -> K(gas):
This step involves the conversion of solid potassium into a gaseous state. To do this, energy input is required as the solid particles gain energy to overcome the intermolecular forces holding them together. Therefore, Step A does not release energy.

B. K(gas) -> K+(gas) + e-:
This step involves the ionization of gaseous potassium atoms to form potassium ions (K+) and the release of electrons (e-). This process requires energy input to remove an electron from the potassium atom, so it does not release energy.

C. Cl(gas) -> Cl-(gas):
This step involves the formation of chloride ions by gaining an electron. Whenever an atom gains an electron, energy is released, so Step C releases energy.

D. Cl(gas) + e- -> Cl-(gas):
This step is the same as Step C, where a chlorine atom gains an electron to form a chloride ion. As mentioned earlier, this process releases energy.

E. K+(gas) + Cl-(gas) -> KCI(solid):
This is the final step where the potassium ion (K+) and chloride ion (Cl-) combine to form solid KCI. The energy required for this step is the lattice energy, which is the energy released when oppositely charged ions come together to form a solid crystal lattice. In this case, since positive and negative ions are coming together to form KCI, energy is released.

Based on our analysis, the steps that release energy during the formation of KCI are C (Cl(gas) -> Cl-(gas)) and D (Cl(gas) + e- -> Cl-(gas)). Therefore, the correct answer is D (D AND E).