In diameter, attached to a stretched fibre and having a M t ru e small magnetic needle fixed to its back, is arranged within a menu.
It is insoluble in water, but gradually decomposes, forming a hydrated oxide, Ru 2 0 5 H 2 O.
It is soluble in water, giving an orangered solution which becomes green on standing, and gradually deposits the hydrated pentoxide, Ru 2 O 5 H 2 O (H.
An oxide of composition Ru 4 0 9 is obtained as a black hydrated powder when the peroxide is heated with water for some time.
Fusion with caustic potash converts it into a mixture of potassium ruthenate and ruthenium sesquioxide, Ru 2 0 3, which is a black, almost insoluble powder.