Lutetium

Lutetium tarnishes slowly in air, and burns readily, forming lutetium(III) oxide, Lu₂O₃.

4 Lu(s) + 3 O₂(g) 2 Lu₂O₃(s)

Lutetium dissolves readily in dilute sulphuric acid, forming colorless Lu(III) ions and hydrogen gas, H₂.

2 Lu(s) + 3 H₂SO₄(aq) 2 Lu³⁺(aq) + 3 SO₄²⁻(aq) + 3 H₂(g)

Lutetium reacts with all the halogens, forming the corresponding lutetium(III) halides.

2 Lu(s) + 3 F₂(g) 2 LuF₃(s)
2 Lu(s) + 3 Cl₂(g) 2 LuCl₃(s)
2 Lu(s) + 3 Br₂(g) 2 LuBr₃(s)
2 Lu(s) + 3 I₂(g) 2 LuI₃(s)

Lutetium reacts slowly with cold water, and quickly with hot water, forming lutetium(III) hydroxide, Lu(OH)₃, and hydrogen gas (H₂).

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