Mr. Johnson, the professor, provided positive feedback on the chart of chemical components which was developed by the students.
2. Conclusive and beyond doubt or question: Janet made a positive identification of the accused robber.3. Confident, optimistic, and focusing on good things rather than bad ones: Jeff had a positive attitude about what he was doing on his job.
4. Producing good results because of some kind of beneficial content: The trip to the zoo was a positive experience for Tim and the other students in the biology class.
5. Encouraging behavior; especially, in the young, that is considered morally good: Henry was a great example of being a positive role model.
6. Used to emphasize the degree to which something is true, striking, or impressive: Viewing the valley from the top of the mountain was a very positive experience.
7. In mathematics, capable of being measured, detected, or perceived: There was a positive correlation between Tom's investment in telecommunications and its economic development.
8. In medicine, indicating the presence of a particular organism or component in the results of a test or examination: The medical tests indicated Susan had tested positive for having TB and so the Dr. Diedrich prescribed medication and rest.
9. That which is measured in a direction, or designated as a quantity, equal in magnitude, but opposite to that regarded as negative: The temperature that was indicated on the thermometer read + 5° Centigrade which is a positive and warming temperature.
10. Having an electrical charge of an opposite polarity to that of an electron and the same polarity as that of a proton: The "+" on a battery indicates that it is the positive end.
11. Relating to the theory that knowledge can be acquired only through direct observation and experimentation: The hands-on approach in the biology class created a positive learning experience for Burton and Sandy.
12. In biology, indicating growth, response, or movement toward a stimulus: Phototropism is the positive growth of a plant towards a light source.
13. Etymology: from about 1300, a legal term meaning "formally laid down"; from Old French positif; from Latin positivus, "settled by arbitrary agreement" as opposed to naturalis, "natural"; from positus, past participle form of ponere, "to put, to place". A positive character stays "put" in his or her opinions.
The sense is broadened to "expressed without qualification" (1598), then "confident in opinion" (1665); mathematical use is from 1704; in electricity, 1755.
The psychological sense of "concentrating on what is constructive and good" is recorded from 1916. Positivism (1847) is the philosophy of Auguste Comte, who published Philosophie positive in 1830.
Positively charged ions are called cations; negatively charged ions are labeled, anions.
Ions are formed by the addition of electrons to, or the removal of electrons from, neutral atoms or molecules or other ions; by combination of ions with other particles; or by rupture of a covalent bond between two atoms in such a way that both of the electrons of the bond are left in association with one of the formerly bonded atoms.
Examples of these processes include the reaction of a sodium atom with a chlorine atom to form a sodium cation and a chloride anion; the addition of a hydrogen cation to an ammonia molecule to form an ammonium cation; and the dissociation of a water molecule to form a hydrogen cation and a hydroxide anion.
Many crystalline substances are composed of ions held in regular geometric patterns by the attraction of the oppositely charged particles for each other.
Ions migrate under the influence of an electrical field and are the conductors of electric current in electrolytic cells.
The positive pole of a galvanic battery or the electrode connected with it.
An electrode toward which negatively charged ions migrate.