The energy associated with objects in motion is called kinetic energy. For example, when an airplane is in flight, the airplane is moving through the air very quickly—doing work to enact change on its surroundings. The jet engines are converting …
Nuclear technology is used in medicine to locate and study diseased tissue using special drugs called radiopharmaceuticals. Radioactive tags are used to identify cancer cells in the bones, brain tumors, and Alzheimer’s disease, and to monitor the function of body …
According to the pressure-flow hypothesis, food is prepared in the plant leaves in the form of glucose. Before moving into the source cells present in the phloem, the prepared food is converted into sucrose. Water moves from the xylem vessels …
The heat of solution referred to as the enthalpy of solution or enthalpy of dissolution, is the enthalpy change associated with the dissolution of a solute in a solvent at constant pressure resulting in infinite dilution. The heat of solution, …
The atomic nucleus is composed of protons and neutrons. The atomic number, Z give the number of protons in the nucleus. The number of neutrons in the nucleus is the neutron number, N. The number of nucleons is mass number, …
Previously, it was thought that the absorption of mineral salts from the soil took place along with the absorption of water, but it is now well established that the mineral salt absorption and water absorption are two different processes. Mineral …
Cathode rays (also called an electron beam) are streams of electrons observed in vacuum tubes. If an evacuated glass tube equipped with two electrodes and a voltage is applied, the glass opposite the negative electrode observed to glow from electrons …
Nuclear fusion is a reaction in which two nuclei are combined to form a larger nucleus; energy is released when light nuclei are fused to form medium-mass nuclei. The amount of energy released by a fusion reaction is known as …
The distribution of a particular disease is dynamic. Changes in the environment, the pathogen, or the host population can dramatically impact the spread of disease. According to the World Health Organization (WHO), an emerging disease is one that has appeared …
Neutral atoms of an element contain an equal number of protons and electrons. The number of protons determines an element’s atomic number (Z) and distinguishes one element from another. For example, carbon’s atomic number (Z) is six because it has …