Rubidium and strontium are both in Period 5 of the Periodic Table. Rubidium is in Group I. Strontium is in Group II. Which statement about these elements is correct?

Each element has five electrons in its outer electron shell.

The atomic number of rubidium is greater than the atomic number of strontium.

Rubidium forms the \(\mathrm{Rb}^{+}\)ion; strontium forms the \(\mathrm{Sr}^{2+}\) ion.

Electrolysis of molten rubidium chloride and of molten strontium chloride produces hydrogen.

Chemistry

IGCSE&ALevel

CAIE

Exam No：0620_m24_qp_12 Year：2024 Question No：26

Answer:

1.1.1. State the distinguishing properties of solids, liquids and gases

1.1.2. Describe the structures of solids, liquids and gases in terms of particle separation, arrangement and motion

1.1.3. Describe changes of state in terms of melting, boiling, evaporating, freezing and condensing

1.1.4. Describe the effects of temperature and pressure on the volume of a gas

1.1.5. Explain changes of state in terms of kinetic particle theory, including the interpretation of heating and cooling curves

1.1.6. Explain, in terms of kinetic particle theory, the effects of temperature and pressure on the volume of a gas