1 Cropping an image means to select a rectangular region to use. 2  To crop an image: 3  Right click on the image file in the File Explorer, select Open With, Paint. 4  Right click on the Select item in the toolbar.  Depress the left mouse button at the upper left corner of the rectangular region you wish to select.
TNT is made by adding 3 NO 2 groups (from nitric acid) to toluene. At low temperatures, the mononitrotoluenes are made, and as the reaction temperature is increased the dinitro compounds are formed, until eventually TNT is formed. TNT is explosive for two reasons. First, it contains the elements carbon, oxygen and nitrogen, which means that when the material burns it produces highly stable substances (CO, CO 2 and N 2) with strong bonds, so releasing a great deal of energy.
Living organisms are composed primarily of carbon, oxygen, and hydrogen. Other elements in living matter include calcium, nitrogen, phosphorus, potassium, and trace amounts of other elements. Water is made up of hydrogen and oxygen. The oceans also contain salt, made up of sodium and chlorine. The atmosphere is mostly made up of the element nitrogen, existing in diatomic form (N2). It also includes oxygen, carbon (in carbon dioxide) and a small amount of other elements.