Naming compounds penta- prefix

Continuing in the alkane series (also called the paraffin series because the first solid hydrocarbon in the series is paraffin, or candle wax), the next compound is pentane. This name is derived from the Greek word penta, for five. As its name implies, it has five carbon atoms, and its molecular formula is C,H12. From pentane on, the Greek prefix for the numbers five, six, seven, eight, nine, ten, and so on are used to name the alkanes, the Greek prefix corresponding to the number of carbon atoms in the molecule. The first four members of the alkane series do not use the Greek... 

The ligands include one Cl- ion and five NH3 molecules. The chloride ion is designated as chloro, and each ammonia molecule is designated ammine. The prefix penta- indicates that there are five NH3 ligands present. The name of the complex cation is therefore pentaamminechloro-cobalt(III). Note that the ligands are named alphabetically, disregarding the prefix. Since the counter ions are chloride ions, the compound is named as a chloride salt ... 

The stoichiometric name of the compound is then formed by combining the name of the electropositive constituent, cited first, with that of the electronegative constituent, both suitably qualified by any necessary multiplicative prefixes ( mono , di , tri , tetra , penta , etc., given in Table IV). The multiplicative prefixes precede the names they multiply, and are joined directly to them without spaces or hyphens. The final vowels of multiplicative prefixes should not be elided (although monoxide , rather than monooxide , is an allowed exception because of general usage). The two parts of the name are separated by a space in English. 

Nearly all binary molecular compormds involve two nonmetals bonded together. Although many nonmetals can exhibit different oxidation numbers, their oxidation numbers are not properly indicated by Roman numerals or suffixes. Instead, elemental proportions in binary covalent compounds are indicated by using a prefix system for both elements. The Greek and Latin prefixes for one through ten are mono, di, tri, tetra, penta, hexa, hepta, octa, nona, and deca. The prefix mono- is omitted for both elements except in the common name for CO, carbon monoxide. We use the minimum number of prefixes needed to name a compound unambiguously. The final a in a prefix is omitted when the nonmetal stem begins with the letter o we write heptoxide, not heptaoxide. ... 

However, it is possible to have two or more substituents that are identical. In other words, there could be two methyl substituents or three ethyl substituents. The rules state that another prefix is used with the substituent di for two, tri for three, tetra for four, penta for five, and hexa for six identical substituents. In this book, molecules with more than six identical substituents are very rare and will be ignored for now. This rule means that two methyl groups are indicated as dimethyl, three ethyl groups are triethyl, and five methyl groups will be pen-tamethyl. When a compound has more than one substituent, but the substituents are the same, first determine the name of the substituent and then insert the multiplying prefix. If there are two or more identical alkyl substituents, the one to be assigned the lower number is the one cited first in the name. 

Answer. Two nonmetals share electrons and form a molecular compound. Br (first nonmetal) is bromine F (second nonmetal) is fluoride. In the name for a molecular compound, prefixes indicate the subscripts in the formulas. The subscript 1 is understood for Br. The subscript 5 for fluoride is written with the prefix penta. The name is bromine pentafluoride. 

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