1. Marca la alternativa correcta: 1. El tercer nivel de energia puede aceptar maximo: a) 4 electiones b) 8 electrones c) 10 electrones d) 18 electrones

57. Rappresenta le equazioni delle seguenti reazioni specificando il nome dei prodotti. \( \begin{array}{ll}\text { a) ossidazione dell'esano } & \text { c) dibromurazione dell'esano } \\ \text { b) monoclorurazione del butano } & \text { d) ossidazione del propano }\end{array} \)

The electronic configuration of one element is \(1s^ 2 2s^ 2 2p^ 6 3s^ 2 3p^ 6 3d^ { 10} 4s^ 1\). What is same group which is recently discovered?

During a reaction, the enthalpy of formation of an intermediate is -286 \( \mathrm{~kJ} / \mathrm{mol} \). During the reaction, 2 moles of the intermediate are produced. What is the enthalpy value for this step of the reaction? A. -572 kJ B. 572 kJ C. 286 kJ D. -286 kJ

Explain,why we cannot call any fresh vegetable or fruit a pure substance?

You need to calculate the enthalpy change \( \left(\Delta H^{0}\right) \) of the reaction \( \mathrm{A}+\frac{1}{2} \mathrm{~B} \rightarrow \mathrm{C} \). How can the enthalpies given for the reaction steps below be combined to give the overall change in enthalpy? \[ \mathrm{A}+\mathrm{B} \rightarrow \mathrm{D} \]