Chemical formulas formulas

The expression that shows the number and kind of each atom in a molecule is the chemical formula. Chemical formulas use the chemical symbol of the atom to express the type of atom and a subscript following the symbol to express the number of atoms in the molecule. If there is only one of a type of atom, no subscript is used. In addition to the number and type of atom, chemical formulas can (but don t have to) suggest the arrangement of the atoms. 

In Chapter 5 we will go over chemical formulas, which are really the words that make up the language of chemistry. The elemental symbols, which are shown on the Periodic Table of Elements, are the letters that make up the (words) chemical formulas. Chemical formulas combine in chemical equations to form the sentences in the language of chemistry. Before you can be expected to correctly write the chemical equations (sentences) or the chemical formulas (words), you must make sure that you are using the elemental symbols (letters) correctly. 

S Formula Chemical formula for a typical sample of the mineral. Composition often varies considerably with the origin of the sample. 

Chemical formulas that indicate the actual numbers of atoms in a molecule are called molecular formulas. (The formulas in Figure 2.18 are molecular formulas.) Chemical formulas that give only the relative number of atoms of each type in a molecule are called empirical formulas. The subscripts in an empirical formula are always the smallest possible whole-number ratios. The molecular formula for hydrogen peroxide is H2O2, for example, whereas its empirical formula is HO. The molecular formula for ethylene is C2H4, and its empirical formula is CH2. For many substances, the molecular formula and the empirical formula are identical, as in the case of water, H2O. 

Molecular formula Chemical formula in which subscripts are used to indicate the number of atoms of each element present in one molecule. In organic compounds, carbon is cited first, hydrogen second, and the remaining elements in alphabetical order. 

Structural formulas Chemical formulas fhaf show fhe connecfions between atoms in molecules as straight lines Molecular formulas Chemical formulas fhaf represenf molecules with atom symbols and subscripts... 

Molecular formulas Chemical formulas that represent molecules with atom symbols and subscripts Molecule The smallest chemical unit of a compound that retains the composition and properties of the compound and can exist independently... 

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