<span>Carbon is the only element capable of forming stable, extended chains of atoms bonded into single, double, or triple bonds.</span>
In the way that a magnifier is usually used, the object is placed closest to the focal point of the lens. As a result, a virtual image is created the furthest where it can be viewed by the naked eye.
Antibiotics are ineffective against viruses<span> because </span>viruses<span> do not have cells.</span>Viruses<span> are infectious agents that live within the cells of other living things. </span>Antibiotics<span>work by breaking down the cell walls of bacteria or interfering with the bacteria's ability to repair its cell's DNA, according to How Stuff Works.</span>
<span>The ischemic penumbra can maintain metabolic demand with marginal blood flow from collateral circulation for a maximum of 50% before increasing in size. A penumbra is the area where the flow of blood at about 25 - 50% can maintain normal metabolic demands for 6 - 8 hours only. When it continues to increase, the human cells will die and other neurological activity will be suspended causing the person to die slowly.</span>