<span>Pathogen is the term for bacteria and virus's are not helpful. They are harmful to other living system and cause disease. All bacteria are not pathogens but all bacterial pathogens are harmful and disease causing. Therefore the correct response is true.</span>
<span>Fayalite has a hardness of 6.5-7 on the Mohs scale. Therefore it scratches orthoclase (hardness 6), but not topaz (hardness 8).HOPE THIS HELPS:]</span>
