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.
We are all made of. stardust. There are many different types of atoms. You probably can name many of them already, such as oxygen, calcium, carbon and iron. We call them elements. And everything on this planet is made up of various combinations of these elements. Including you.