Melissa Stuart, Megan Pyne, & Amanda Ward Period 1 Chemistry

Similarities amidst All Elements in Group 17  All have seven valence electrons  Called “halogens”  All nonmetals  “They all exist as diatomic molecules at room temperature and oxidize metals to form halides.” (cited, cited 2)citedcited 2  When going down the group, both the melting points and boiling points increase. In comparison to the Group 2 elements, the melting points are extremely low. (cited)cited  “The most characteristic chemical feature of the halogens is their ability to oxidize.” (cited)cited  Halogens have a tendency to react a lot more drastically than other elements because of their seven valence electrons. Since they only need one more electron to become a full octet, they’re more likely to react with higher impact.

Fluorine, F  Type of Element: Nonmetal  Appears as pale yellow gas at room temperature  Practical use: Used in toothpastes, refrigerants, air conditioning, and some water supplies (to prevent tooth decay)  Element is very reactive; reacts with all elements with the exceptions of helium, neon, and argon.

Chlorine, Cl  Type of Element: Nonmetal  Appears as a light green gas at room temperature  Practical uses: Used to keep water clean, paper products, dyes, plastics, solvents, chloroform, and other consumer products.

Bromine, Br  Type of Element: Nonmetal  Reddish-brown liquid at room temperature  Practical uses: Used in photography film, pesticides, sanitizers, dyes, and swimming pools.  Prolonged use is said to cause thyroid gland dysfunction and even cancer.

Iodine, I  Type of Element: Nonmetal  Looks like a “violet solid” at room temperature  Practical uses: Used in organic chemistry, medicinal purposes, and photography (film developing)

Astatine, At  Type of Element: Nonmetal  “Black metallic solid” at room temperature (cited)cited  Practical uses: Used in cancer treatment, but can accumulate in the thyroid gland if used too much.