Molecules are held together by either covalent bonding or ionic bonding. Several types of non-metal elements exist only as molecules in the environment. For example, hydrogen only exists as hydrogen molecule. A molecule of a compound is made out of two or more elements.
In general, chiropractic services range from approximately $30 to $200 per session. Of course, each type of treatment has a different cost. For example, an initial consultation with a chiropractor may be provided at no charge, while a typical therapy session costs about $65 on average.
Chiropractors who work for a college or university earn $92,000 per year. In 2010 chiropractors were earning $67,200 each year, which translates to $32.31 per hour. In 2013 the average salary for a chiropractor was $132,089.