Polar covalent molecules<span> exist whenever there is </span>an<span> asymmetry, or uneven distribution of electrons in a </span>molecule<span>. </span>One<span> or </span>more<span> of these asymmetric atoms pulls electrons </span>more<span> strongly </span>than<span> the </span>other<span>atoms. For example, the </span>polar<span> compound methyl alcohol has a </span>negative<span> pole made of carbon and hydrogen and a positive ...</span>
An introduced species is a non native species that has one way or another been integrated into the native environment by human or other means.
An invasive species on the other hand is an introduced organism that has become detrimental to the local environment.
