Electrons, Energy Levels & Atomic Orbitals (Cambridge (CIE) A Level Chemistry): Exam Questions

Complete Table 2.1 with information for two of the subatomic particles in an atom of ¹⁹⁷Au.

Table 2.1

i) Define the term isotope.

[2]

ii) Explain why different isotopes of gold have identical chemical properties.

[1]

Gold(III) chloride has the formula AuCl₃.

Complete Fig. 2.1 to show the electronic configuration of the chloride ion, Cl^-, using the electrons in boxes notation.

Fig. 2.1

Sketch the shapes of an s orbital and a p orbital on the axes in Fig. 2.2. Label each type of orbital.

Fig. 2.2

State the full electronic configuration of a chromium atom.

i) State what the symbol [Ar] represents.

[1]

ii) Complete Fig. 2.1 to show the electronic configuration of a chromium atom using the electrons in boxes notation.

[1]

Fig. 2.1

This question is about the chromium(III) ion, .

i) Deduce the number of protons, neutrons, and electrons in a ⁵²Cr³⁺ ion.

protons ..........................

neutrons ..........................

electrons ..........................

[1]

ii) State the full electronic configuration of a chromium(III) ion.

[1]

i) State the full electronic configuration of a rubidium ion, Rb⁺.

[1]

ii) Compare the ionic radius of a rubidium ion to the atomic radius of a krypton atom. Explain your answer.

[2]

The third shell consists of the 3s, 3p and 3d sub-shells.

i) State the total number of orbitals present in the third shell.

[1]

ii) List the 3d, 4s and 4p sub-shells in order of increasing energy.

[1]

Rubidium forms an ionic compound with selenium, Rb₂Se.

Complete Fig. 3.1 to show the electronic configuration of the valence electrons in a selenium atom.

Fig. 3.1

In the blast furnace, carbon reacts with a limited supply of oxygen to form carbon monoxide.

Write an equation for this reaction.

i) Identify the highest energy sub-shell occupied by electrons in an oxygen atom.

[1]

ii) Sketch the shape of an orbital from this sub-shell on the axes in Fig. 5.1.

Fig. 5.1

[1]

i) Complete Fig. 5.2 to show the electronic configuration of a carbon atom in the ground state.

Fig. 5.2

[1]

ii) A molecule of carbon monoxide, CO, contains a triple covalent bond.

Deduce the hybridisation of the carbon atom in carbon monoxide.

[1]

iii) Describe how the σ and π bonds form in a molecule of carbon monoxide. Refer to orbital overlap in your answer.

[3]