Litmus "Lecanora tartarea" (Norway, Sweden), "Variolaria dealbata", "Ochrolechia parella", "Parmotrema tinctorum", and "Parmelia". Currently, the main sources are "Roccella montagnei" (Mozambique) and "Dendrographa leucophoea" (California). The main use of litmus is to test whether a solution is acidic or basic. Wet litmus paper can also be used to test for water-soluble gases that affect acidity or alkalinity; the gas dissolves in the water and the resulting solution colors the litmus paper. For instance, ammonia gas, which is alkaline, turn the red litmus paper blue. Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or
SAT Subject Test in Chemistry between the SAT Chemistry Test and the AP Chemistry exam, which is a more critical-thinking exam that is used not for college admissions but rather for college placement. Still, an AP course in Chemistry is sufficient preparation for the Chemistry SAT. The student is not allowed to use notes, textbooks, or a calculator on this test. The only resource a student may use is a periodic table which is provided with the test booklet. This table only provides atomic masses, atomic numbers, and symbols for each element. SAT Subject Test in Chemistry The SAT Subject Test in Chemistry is a