Holly has an unknown substance in a beaker. she wants to determine the relative ph of the unknown substance. she places a piece of blue litmus paper into the substance, and the litmus paper turns red. the substance in the beaker

Blue litmus paper turns red in the presence of an acid. Therefore, it can be assumed that the substance in the beaker is an acid.

Acids have a pH level of less than 7. Consequently, it can be assumed that the substance has a pH level less than 7.

i believe the answer is a.

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.