Regents Chemistry Exam August 2025 Question 13 13  Which substance can not be broken down by a chemical change? (1) manganese (2) ethene (3) propanal (4) water Solution: Elements can not be broken down by a chemical change. All element names can be found in Table S on the Reference Table. Choice 1, manganese, is an element and is the correct answer. LINKS: Regents Chemistry Guides and Solutions Chemistry Tutoring More Regents Chemistry Practice

Regents Chemistry Exam August 2025 Question 12 12  A sample of NaCl(s) and a sample of NaCl(l) have (1) the same phase and the same physical properties (2)the same phase and different physical properties (3) different phases and the same physical properties (4) different phases and different physical properties Solution: (s) refers to solid and (l) refers to liquid. Two samples of solid and liquid NaCl will have different phases and different physical properties. Choice 4 is