Chapter 20 - The Representative Elements

Hydrogen sulfide

________ is a strong reducing agent in aqueous solution, producing a milky- looking suspension of finely divided sulfur as one of the products.

Phosphine

________ is analogous to ammonia, although it is a much weaker base and much less soluble in water.

OF2

The name for ________ is oxygen difluoride rather than difluorine oxide because fluorine has a higher electronegativity than oxygen and thus is named as if it were an anion.

Nitrogen

________ forms a series of oxides including N2O, NO, NO2, and N2O5.

natural world

In the ________, nitrogen fixation occurs through nitrogen- fixing bacteria the root nodules of certain plants and through lightning in the atmosphere.

Fluorine

________ forms only one oxyacid, hypofluorous acid, but at least two oxides.

elemental forms

The ________ are called rhombic and monoclinic sulfur, both of which contain S8 molecules.

organic compounds

Most high explosives are ________ that, like nitroglycerin, contain nitro groups and produce nitrogen and other gases as products.

Ozone

________ can be prepared by passing an electric discharge through the pure oxygen gas.

Elements

________ show a wide variety of chemical properties.

Hydrazine

________ (N2H4) is a powerful reducing agent.

Hydration

________ becomes more exothermic as the charge density of an ion increases.

Haber process

The ________ is one example of nitrogen fixation.

Phosphorus

________ is very reactive and bursts into flames on contact.

fluoride

When dissolved in water, the hydrogen halides behave as acids, and all except hydrogen ________ are completely dissociated.

Azeotrope

________: A solution that distills at a constant temperature without a change in composition 20.3 The Chemistry of Phosphorus.

Ammonia

________ is the most important hydride of nitrogen.

P4O6

Phosphorus forms oxides including ________ and P4O10 20.2 The Chemistry of Nitrogen.

Fluoride ions

________ added to drinking water and toothpaste help prevent tooth decay because fluorapatite is less soluble in the acids of the mouth than hydroxyapatite.

Nitric acid

________ is an important industrial chemical used in the manufacture of many products, such as nitrogen- based explosives and ammonium nitrate for use as fertilizer.

mineral hydroxyapatite

The ________, the principal component of tooth enamel, can be converted to fluorapatite by reaction with fluoride.

monatomic gases

All elements are ________ and are generally very unreactive.

terminal oxygens

The ________ are the nonbridging oxygen atoms.

Helium

________ was identified by its characteristic emission spectrum as a component of the sun before it was found on earth.

decomposition of nitroglycerin

The ________ is a complex process that occurs in many steps.

pyramidal NH3 molecules

It contains ________.

ozone layer

The ________ is especially important because it absorbs ultraviolet light and thus acts as a screen to prevent radiation 20.6 The Chemistry of Sulfur.

Nitrogen

________ and phosphorus are nonmetals.

Phosphine

________ (PH3) has bond angles close to 90 degrees.

Haber process

The ________ is a synthetic method of nitrogen fixation.

elemental forms

Exists in three ________: white (contains P4 molecules), red, and black.

Nitric acid

________ is a very important strong acid manufactured by the Ostwald process.

Haber process

They produce ammonia at soil temperature and 1 atm of pressure, whereas the ________ requires severe conditions of 400°C and 250 atm.

Ozone

________ exists naturally in the upper atmosphere of the earth.