Which statement explains one of the decreases in first ionization energy (I.E.) across period 3?

A.     The nuclear charge of element Al is greater than element Mg.

B.     The electron-electron repulsion is greater, for the electron with the opposite spin, in element S than in element P.

C.     A new sub-level is being filled at element S.

D.     The p orbital being filled in element Al is at a lower energy than the s orbital in element Mg.

Sketch a graph of the first six ionization energies of calcium.

Explain why an aluminium-titanium alloy is harder than pure aluminium.

Which of the following transitions in the hydrogen atom emits the least energy?

A. n = 2 to n = 1

B. n = 3 to n = 1

C. n = 4 to n = 2

D. n = 4 to n = 3

The graph represents the first ten ionisation energies (IE) of an element.

What is the element?

A. O

B. S

C. Ne

D. Cl

Hydrogen spectral data give the frequency of 3.28 × 10¹⁵ s⁻¹ for its convergence limit.

Calculate the ionization energy, in J, for a single atom of hydrogen using sections 1 and 2 of the data booklet.

(i) Explain the convergence of lines in a hydrogen emission spectrum.

(ii) State what can be determined from the frequency of the convergence limit.

The first six ionization energies, in kJ mol^–1, of an element are given below.

Explain the large increase in ionization energy from IE₃ to IE₄.

Plot the relative values of the first four ionization energies of sodium.

Sketch a graph of the first six successive ionization energies of vanadium on the axes provided.

Determine, showing your working, the wavelength, in m, of ultraviolet light absorbed by a single molecule in one of these steps. Use sections 1, 2 and 11 of the data booklet.

Explain why the first ionization energy of nitrogen is greater than both carbon and oxygen.

Nitrogen and carbon:

Nitrogen and oxygen:

The electron configuration of copper makes it a useful metal.

Determine the frequency of a photon that will cause the first ionization of copper. Use sections 1, 2 and 8 of the data booklet.

Explain why the first ionization energy of sulfur is lower than that of phosphorus.

Sodium emits yellow light with a frequency of 5.09 × 10¹⁴Hz when electrons transition from 3p to 3s orbitals.

Calculate the energy difference, in J, between these two orbitals using sections 1 and 2 of the data booklet.

Darling, D, n.d. D lines (of sodium). [online] Available at <https://www.daviddarling.info/encyclopedia/D/D_lines.html> [Accessed 6 May 2020].