Reactivity

Reactivity refers to the rate at which a chemical substance tends to undergo a chemical reaction in time. In pure compounds, reactivity is regulated by the physical properties of the sample. For instance, grinding a sample to a higher specific surface area increases its reactivity. In impure compounds, the reactivity is also affected by the inclusion of contaminants. In crystalline compounds, the crystalline form can also affect reactivity. However in all cases, reactivity is primarily due to the sub-atomic properties of the compound.

Ornithology

Ornithology (from Greek: ὄρνις, ὄρνιθος, ornis, ornithos, "bird"; and λόγος, logos, "knowledge") is a branch of zoology that concerns the study of birds. Several aspects of ornithology differ from related disciplines, due partly to the high visibility and the aesthetic appeal of birds. Most marked among these is the extent of studies undertaken by amateurs working within the parameters of strict scientific methodology.

Matriculation

Matriculation, in the broadest sense, means to be registered or added to a list, from the Latin matrix. In Scottish heraldry, for instance, a matriculation is a registration of armorial bearings. The most common meaning, however, refers to the formal process of entering a university, or of becoming eligible to enter by acquiring the meeting prerequisites.

Wikipedia has an incredible article about this.