Particles in the Atom & Atomic Radius (Cambridge (CIE) AS Chemistry): Exam Questions

Complete Table 1.1 to show the relative charge and relative mass of the subatomic particles.

Table 1.1

State the block in the Periodic Table in which silicon is placed. Explain your answer.

A mass spectrometer can be used to determine the isotopic abundances of an element. The mass spectrum of a sample of silicon shows that it contains three isotopes, ²⁸Si, ²⁹Si and ³⁰Si.

i) Define the term isotope.

[1]

ii) The isotopic abundances of the sample are shown in Table 1.2.

Table 1.2

Calculate the relative atomic mass, A_r, of this sample of silicon. Give your answer to two decimal places.

A_r = ......

[1]

Using your Periodic Table, complete Table 1.1

Table 1.1

Sodium is an element in Period 3. State and explain the trend in atomic radius across Period 3.

Chlorine is an element in Period 3 which has an atomic radius of 0.099 nm. The chloride ion has an ionic radius of 0.181 nm.

Explain the difference between the two radii.

Complete Table 3.1 to show the composition of the given species.

Table 3.1

Beams of protons, neutrons and electrons behave differently in an electric field.

Fig. 3.1 shows the path of a beam of electrons in an electric field.

On Fig. 3.1, draw and label the paths of a beam of protons and a beam of neutrons.

Fig. 3.1

Chlorine and sulfur are elements in Period 3.

Explain why the atomic radius of a chlorine atom is smaller than that of a sulfur atom.

Table 4.1 below shows the atomic radii for the elements of Period 2, Li to F.

Table 4.1

i) State and explain the trend in atomic radius across Period 2.

[3]

ii) Suggest why the atomic radius of neon cannot be determined in the same way as the other Period 2 elements.

[2]

Complete Fig. 4.1 to show the full electronic configuration of a boron atom in the ground state.

Fig. 4.1

Explain why the first ionisation energy of boron is lower than the first ionisation energy of beryllium.

The successive ionisation energies for another element, J, are shown in Table 4.2.

Table 4.2

Deduce the formula of the compound formed when element J reacts with chlorine.