The technique allows you to discard unnecessary or unwanted portions of an image is cropping.
<h3>What is cropping?</h3>
The term cropping has to do with the removal of information or the parts of a picture that is not needed. We use it when we want a picture to reflect a given detail and the excesses removed. In this modern age, it is common to snap pictures by the use of digital tools and hand held equipment. This electronic gadgets often have provisions for the user to discard unnecessary or unwanted portions of an image thereby retaining only the part of the image that may be deemed to be necessary.
Thus the technique allows you to discard unnecessary or unwanted portions of an image is cropping.
There are 6 atoms because so2, which is sulfur dioxide, has a total of 3 subscripts that is multiplied by 2 because of the coefficient in front of so2.