S1.2 The nuclear atom Questionbank

State the type of bonding present in sodium chloride and in carbon tetrachloride.

Explain why sodium chloride does not conduct electricity in the solid state but does when molten.

Suggest why carbon tetrachloride does not conduct electricity in any state.

Use the diagram and your knowledge of structure and bonding to deduce which substance(s) contain delocalized ions.

State and explain the difference in melting point between sodium chloride and carbon tetrachloride.

Predict the state of carbon tetrachloride at room temperature. Justify your answer based on its intermolecular forces.

Draw the Lewis (electron dot) structure for the $Na^+$ ion and a $CCI_4$ molecule

State what the energy value of 0 kJ mol^-1 represents for the He⁺ ion.

Calculate the wavelength, in nm, of the photon emitted when an electron falls from $n=4$ to $n=2$. (Planck’s constant $h = 6.63 \times 10^{-34}\ \mathrm{J\ s}$, speed of light $c = 3.00 \times 10^8\ \mathrm{m\ s^{-1}}$)

Determine the first ionization energy of the He⁺ ion in $\mathrm{kJ}\ \mathrm{mol}^{-1}$ .

Compare the energy required for the electron transitions from $n=2$ to $n=3$ for the He⁺ ion and the H atom.

Sketch a diagram showing the emission spectrum for He⁺ corresponding to transitions ending at $n=1$ (Lyman series), indicating the trend in line spacing.

Discuss why the emission lines converge at high frequencies, and how this convergence relates to ionization.

State the number of protons in both isotopes.

Deduce the number of neutrons in each isotope.

Explain why the chemical properties of these two isotopes are almost identical.

Define the term isotope.

State the number of protons and neutrons in ${^{99m}Tc}$.

Explain why isotopes of the same element have similar chemical properties.

Identify one use of isotopes in medicine and explain briefly how the isotope works.

State the number of electrons in a neutral atom of carbon-14.

Compare the atomic structure of carbon-12 and carbon-14.

State what is represented by the two smaller peaks at $\mathrm{m} / \mathrm{z}=79$ and 81.

Explain why there are three larger peaks at $\mathrm{m} / \mathrm{z}$ values of 158,160 , and 162 .

Deduce the identities of the species responsible for the peaks at $\mathrm{m} / \mathrm{z}=158$ and $\mathrm{m} / \mathrm{z}=162$.

Calculate the relative atomic mass ($A_r$) of bromine based on the data for the peaks at 79 and 81. (Assume 50% relative abundance for both $^{79}\text{Br}$ and $^{81}\text{Br}$)

State what is represented by the x -axis labeled " $\mathrm{m} / \mathrm{z}$ ".

Identify the species responsible for the peak at $\mathrm{m} / \mathrm{z}=18$.

Suggest the likely species responsible for the peaks at $\mathrm{m} / \mathrm{z}=17$ and 16.

Explain why the peak at $\mathrm{m} / \mathrm{z}=18$ is the most intense.

Predict what effect the presence of a small amount of heavy water ($D_2O$, where $D =$ $^2$H) would have on the mass spectrum.