Amalgam (dentistry) packs the plastic mass, before it sets, into the cavity. The amalgam expands ≈0.1% over 6–8 hours on setting. The final structure is a metal matrix composite, where γ, η and γ phases, are a matrix for unreacted original alloy, minus the fast-reacting β-phase and excess Sn. Amalgam is a mixture of two or more metals (alloy) with mercury which has been purified first by distillation to remove impurities. Currently, major components of the alloy are silver tin and copper. The composition of the alloy powder is controlled by ISO standard for dental amalgam alloy (ISO 1559) to control the
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