Gadolinium

Gadolinium metal dissolves readily in dilute sulphuric acid, forming colourless Gd(III) ions and hydrogen gas, H₂.

2 Gd(s) + 3 H₂SO₄(aq) 2 Gd³⁺(aq) + 3 SO₄²⁻(aq) + 3 H₂(g)

Gadolinium react slowly with O₂ at room temperature, and burns readily, forming gadolinium(III) oxide, Gd₂O₃.

4 Gd(s) + 3 O₂(g) 2 Gd₂O₃(s)

Gadolinium metal reacts with all the halogens, forming the corresponding gadolinium(III) halides.

2 Gd(s) + 3 F₂(g) 2 GdF₃(s) [white]
2 Gd(s) + 3 Cl₂(g) 2 GdCl₃(s) [white]
2 Gd(s) + 3 Br₂(g) 2 GdBr₃(s) [white]
2 Gd(s) + 3 I₂(g) 2 GdI₃(s) [yellow]

Gadolinium reacts slowly with cold water, and quickly with hot water, forming gadolinium hydroxide, Gd(OH)₃, and hydrogen gas (H₂).

2 Gd(s) + 6 H₂O(g) 2 Gd(OH)₃(aq) + 3 H₂(g)