Answer:
The number of protons also determines the identity of the element. ... Since the atom is electrically neutral, the number of electrons must equal the number of protons.
C. rate = k[C4H9Br]
The slow step is always the rate-determining step. In the slow step, C4H9Br is the only reactant and has a coefficient of 1, so it is first order in the rate law.
Answer:
The question is incomplete and confusing.
- In the complete ionic equation you write all the ions that are formed. Those are: Pb²⁺, NO₃⁻, K⁺, and I⁻. They all are present in the complete ionic equation.
- In the net ionic equation, the spectator ions do not appear. They are: NO₃⁻ and K⁺. They would not be present in the net ionic equation, but they do in the complete ionic equation.
See below the details.
Explanation:
Which compound will not form ions?
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<u>1. Write the balanced molecular equation:</u>
- Pb(NO₃)₂(aq) + 2KI(aq) → PbI₂(s) + 2KNO₃(aq)
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<u>2. Write the ionizations for the ionic aqueous compounds:</u>
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- Pb(NO₃)₂(aq) → Pb⁺²(aq) + 2NO₃⁻(aq)
- 2KI(aq) → 2K⁺(aq) + 2I⁻(aq)
- 2KNO₃(aq) → 2K⁺(aq) + 2NO₃⁻(aq)
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<u>3. Write the complete ionic equation:</u>
Pb⁺²(aq) + 2NO₃⁻(aq) + 2K⁺(aq) + 2I⁻(aq) → PbI₂(s) + 2K⁺(aq) + 2NO₃⁻(aq)
Hence, since PbI₂(s) does not ionize, but stays in solid form, it will not form ions.
All, Pb⁺², NO₃⁻, K⁺, and I⁻ will be present in the total ionic equation.
It is in the net ionic equation that the spectator ions are removed. Those, are NO₃⁻ and K⁺, because they are on both sides of the complete ionic equation.
Ans: B) semiconductor
Photovoltaic cells work by converting light energy to electrical energy. These cells are essentially made of silicon based semiconductors. When photons (light energy) strike the surface of the semiconducting material electrons are let loose. The delocalization of electron creates a flow of charge which produces electricity.
Thus, it is the semiconductor present in a photovoltaic cell which is responsible for converting light to electricity.
