As a group, halogens exhibit highly variable physical properties. Halogens 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.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.
A gene can exist in many different forms, calledalleles. For example, letâs say that there is one gene which determines the color of your hair. That one gene may have many forms, or alleles: black hair, brown hair, auburn hair, red hair, blond hair, etc. You inherit one allele for each gene from your mother and one from your father. Each of the two alleles you inherit for a gene each may be strong (dominant) or weak (recessive).
Red hair varies from a deep burgundy through burnt orange to bright copper. It is characterized by high levels of the reddish pigment pheomelanin and relatively low levels of the dark pigment eumelanin.The term redhead has been in use since at least 1510.n Asia, genetic red hair is rare, but can be found in the Levant (Cyprus, Syria, Lebanon, Jordan, Israel and Palestine), in Turkey, in Caucasia, in Northern Kazakhstan, among Uighurs and among Indo-Iranians.