Which of the following represents the sublevels from which the electrons are lost-when the atom of the element \( { }_{21} \mathrm{Sc} \) is converted to \( \mathbf{M}^{3+} \) ion ? \( \begin{array}{ll}\text { (i) } 3 s, 4 s & \\ \text { c) } 3 d, 4 p & \text { (d) } 4 s, 4 p\end{array} \)

14 Nitrogen has atomic number 7 and oxygen has atomic number 8 What is total number of electrons in \( \left(\mathrm{NO}_{3}\right)^{-} \)ion ? \( \begin{array}{ll}\text { (a) } 15 \mathrm{e}^{-} & \text {(b) } 31 \mathrm{e}^{-} \\ \text {(c) } 32 \mathrm{e}^{-} & \text {(d) } 46 \mathrm{e}^{-}\end{array} \)

10 Essay 5 points Please identify the following components for the element Selenium: 1 Chemical Symbol 2. Atomic Number 3. Family \# 4. Valence Electrons 5. Category Edit View Insert Format Tools Table

3.48 The empirical formula of a compound is CH . If the molar mass of this compound is about 78 g , what is its molecular formula?

Based on bond type, which compound has the highest melting point? 1. \( \mathrm{CH}_{3} \mathrm{OH} \) 2. \( \mathrm{C}_{6} \mathrm{H}_{14} \) 3. \( \mathrm{CaCl}_{2} \) 4. \( \mathrm{CCl}_{4} \)

possible Find the hydrogen ion concentration of a solution whose pH is 7.1 . Use the formula \( \mathrm{pH}=-\log \left[\mathrm{H}^{+}\right] \)