On the analysis of something as a base or an acid
On the properties of something, there are different opinions on the distinction between acid and base. The study of "Is Hf A Base Or Acid" should be analyzed by reason.

The ancient sages have long argued that the human substance is classified as an acid or alkali. In the past, based on its compatibility with water, the change of its ions was viewed. If it dissolves and releases hydrogen ions, it is often called an acid; if it produces hydroxide ions, it is mostly classified as a base.

As for Hf, if you want to determine it as an acid or a base, you must first consider its state in water. However, the nature of Hf cannot be directly determined. Or observe the reaction between it and other things to deduce its quality. In various reactions, observe the situation of its gain and loss of protons. If you get a proton, it is close to the nature of a base; if you give a proton, it is similar to the quality of an acid.

And the acid-base properties of things also vary with the environment. Different solvents and different conditions can make things behave differently. Therefore, if you want to determine whether Hf is an acid or a base, you can't be limited to one end. You must consider it comprehensively and observe its reaction in various situations before you can make a clear decision. In fact, you need to be rigorous and study the nature of things to get the true meaning of "Hf is an acid or a base".