Vocabulary: Sparingly soluble means only a small amount of substance dissolves in water.

Example: The reaction equation: Ca$s$ + 2H₂O$l$ → Ca(OH)₂(aq) + H₂$g$

Highlight: Hydroxide solubility increases down the group while sulfate solubility decreases, with BaSO₄ being notably insoluble.

Definition: A precipitate is an insoluble solid formed when two solutions react.

Example: Adding hydroxide ions to Group 2 metal solutions produces white precipitates of varying thickness depending on solubility.

Highlight: The test for sulfate ions uses barium chloride solution, producing a white BaSO₄ precipitate.

Example: Barium sulfate is used in X-ray imaging as a "barium meal" due to its X-ray opacity.

Highlight: Magnesium plays a crucial role in titanium extraction as a reducing agent.

Vocabulary: Wet scrubbing refers to the process of removing sulfur dioxide from industrial gases using calcium compounds.

Definition: First ionization energy is the energy required to remove one electron from a neutral atom.

Highlight: All Group 2 elements form 2+ ions by losing two electrons during reactions.

Example: The trend in melting points can be seen from Beryllium (Be) to Radium (Ra), with a general decrease down the group except for magnesium's unusual crystal structure.