Rosenberg MJ, Meyers A, Roy V. Efficacy, cycle control, and side effects of low- and lower-dose oral contraceptives: a randomized trial of 20 micrograms and 35 micrograms estrogen preparations. Contraception 1999; 60:321. Gallo MF, Nanda K, Grimes DA, Schulz KF. 20 mcg versus >20 mcg estrogen combined oral contraceptives for contraception. Cochrane Database Syst Rev 2005; :CD003989. Bachmann G, Korner P. Bleeding patterns associated with oral contraceptive use: a review of the literature.
A molecule is formed from two or more atoms of a single element. An example is h2o. two hydrogen atoms and one oxygen atom forming a molecule of water! This question is archived.
Best Answer: An atom can be any one of the elements. A molecule is a combination of atoms into a single substance. A compound is a molecule that includes atoms of two different elements. Organelles are parts of cells made up of many, many atoms, such as the mitochondria. Elements are the simpliest form of complete matter, for example a single hydrogen (H) atom.