Chemistry Exam Latest Exam 2025 2026 Solved Questions & Answers Verified 100% Graded A+ (Latest Version)

Page 1 of 88 Chemistry EXAM LATEST EXAM 2025 - 2026 SOLVED QUESTIONS & ANSWERS VERIFIED 100% GRADED A+ (LATEST VERSION) WELL REVISED AND HIGHLY RECOMMENDALE 100% GUARANTEE PASS chemistry exam If 20 molecules of diatomic oxygen (O2) and 56 molecules of diatomic hydrogen (H2) react, how many molecules of water can form? a. 40 b. 20 c. 56 d. 28 e. none of them 40 The relationship between 13C and 12C is called a. isotopes b. isotones c. elements d. compounds e. none of them isotopes The number of neutrons are in U-238 (238 is mass number) a. 92 b. 146 c. 238 d. 96 e. none of them 146Page 2 of 88 1. Isotope of iodine used for treating hyperthyroid in medicine, which has 78 neutrons, what is the mass number of that isotope? a. 54 b. 53 c. 127 d. 131 e. 128 131 The composition of water (ice, liquid or water vapor) always yields 88.81% oxygen and 11.19% hydrogen by mass, which illustrates: a. Daltons atomic theory b. Democritus atomic theory c. The law of definite proportions d. The law of conservation of mass The law of definite proportions Which of the following is a heterogeneous