Chemical Names and Formulas

1. Chemical Names and Formulas Chapter 6 Part I

2. Elements • Robert Boyle (1627–1691) redefined an element to be a substance that could not be broken down into simple substances and questioned the elemental nature of Aristotle’s foursome.

3. Elements are the building Blocks • Elements make up all things living and nonliving. • Chemical combinations of about 100 elements make up an almost limitless number of compounds.

4. Naming • An important part of your chemistry education is the ability to name these compounds. • In nature, only the noble gases exist as monatomic.

5. Compounds • A substance formed by a combination of elements, in a fixed proportion. • (See Dalton) • Compounds cannot be separated by physical means. • Ionic & Covalent

6. Molecules • Many elements found in nature exist as molecules. • Molecules are chemical combinations of elements. • Molecules are the smallest electrically neutral unit of a substance that still has all its properties.

7. Diatomic Molecules • Diatomic molecules are HONClBrIF • Hydrogen • Oxygen • Nitrogen • Chlorine • Bromine • Iodine • Fluorine

8. Ions • Not all substances are molecular. • If they have an electrical charge they are not molecules, but IONS. • When the number of protons and electrons in a molecule are not equal that results in the formation of an ION.

9. Anions • Atoms of nonmetal elements tend to accept electrons and take on a negative charge. • An anion has a negative charge. • For example: Cl-

10. Cations • Atoms of metals tend to lose electrons and take a positive charge. • Cations are atoms with a positive charge. • Example: Na+

11. Ionic Compounds • Ionic compounds are made up of cations and anions. • These are also known as salts. • The most common example is table salt or sodium chloride.

12. Molecules • Molecules are made up of elements that share electrons. There is no charge involved. • These are formed between two non-metals.

14. Molecular and Ionic Characteristics