They are found in all three states of existence. Here are some other physical properties of halogens that make them a very unique family of elements. Appearance Appearance wise fluorine exists as a pale yellow gas that is poisonous in nature, while chlorine is similarly poisonous but exists as a pale green colored gas.alogens range from solid (I2) to liquid (Br2) to gaseous (F2 and Cl2) at room temperature. The chemical properties are more uniform. The halogens have very high electronegativities. Fluorine has the highest electronegativity of all elements.
An example of a phenotypic trait is hair color; there are underlying genes that control the hair color, which make up the genotype, but the actual hair color, the part we see, is the phenotype.
For example, a person with red hair doesn't have the red hair gene while a person with brown hair has the brown hair gene.. Instead, all people have genes for hair color, and different versions of these genes dictate whether someone will be a redhead or a brunette.