The world's second nuclear explosion was achieved with uranium-235. This isotope is unstable and fissions when struck by a neutron. It is, however, found in natural uranium at a concentration of only 0.7 percent. To be useful in nuclear weapons, the concentration must be increased.
Introduction. Influenza, or flu, is a caused by a virus infecting the respiratory system, meaning your nose, throat, bronchial tubes, and lungs. Flu symptoms are usually more severe than those of the common cold and are more likely to affect other parts of your body.
A Honor Society of Nursing (STTI) answered. Viruses affect the body by attacking your cells. They can cause mild to severe symptoms. Viruses can affect only certain cells in your body, like those of your upper respiratory system, causing common cold symptoms.