alkaline earth metals are highly chemically reactive
calcium is alkaline_earth_metal. magnesium is alkaline_earth_metal. group_2_elements is alkaline_earth_metals. alkaline_earth is metallic_element. arsenic_acid is chemically_acidic_substance. hydrogen is very_reactive. pure_iron is very_reactive_chemically. hydrogen_metal is alkali. aluminium_hydroxide is chemical_compound. hydrogen_sulfide is chemically_acidic_substance.