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.
The genotype of an organism is the inherited instructions it carries within its genome. This genotype-phenotype distinction was proposed by Wilhelm Johannsen in 1911 to make clear the difference between an organism's heredity and what that heredity produces. The distinction is similar to that proposed by August Weismann, who distinguished between germ plasm (heredity) and somatic cells (the body).