Complex sentence: Similar to other alkali metals, rubidium metal reacts violently with water, forms amalgams with mercury, and alloys with gold, iron, caesium, sodium, and potassium, but not lithium (even though rubidium and lithium are in the same group).
Split into simpler sentences: Similar to other alkali metals, rubidium metal reacts violently with water. It forms amalgams with mercury and alloys with gold, iron, caesium, sodium, and potassium, but not lithium (even though rubidium and lithium are in the same group).