This quiz works best with JavaScript enabled. Home > Science > Chemistry > Chemistry – Quiz 25 🏠 Homepage 📘 Download PDF Books 📕 Premium PDF Books Chemistry Quiz 25 (20 MCQs) Quiz Instructions Select an option to see the correct answer instantly. 1. The ..... is the sum of the protons and the neutrons in an atom. A) Atomic Number. B) Mass Number. C) Protons. D) Neutrons. Show Answer Correct Answer: B) Mass Number. 2. Chemical formula of quick lime is: A) CaO. B) Ca(OH)2. C) CaCO3. D) CO2. Show Answer Correct Answer: A) CaO. 3. Which among the following is an element? A) Brass. B) Bronze. C) Silver. D) Stainless steel. Show Answer Correct Answer: C) Silver. 4. What are the smallest parts of pure substancesthat cannot be broken down intosimpler substances? A) Mixtures. B) Elements. C) Atoms. D) Molecules. Show Answer Correct Answer: C) Atoms. 5. This ranges 7 on a Ph scale A) Neutral. B) Base. C) Acid. D) None of above. Show Answer Correct Answer: A) Neutral. 6. What is the volume of 150. grams of lead if it has a density of 11.3 g/cm 3? A) 13.3 g. B) 13.3 cm3. C) .075 g. D) 1695 cm3. Show Answer Correct Answer: B) 13.3 cm3. 7. Chewing food to break it down into smaller particles represents a ..... change, but the changing of starch into sugars by enzymes in the digestive system represents a ..... change. A) Chemical then Physical. B) Physical then Chemical. C) Both Physical. D) Both Chemical. Show Answer Correct Answer: B) Physical then Chemical. 8. What is a pure substance made of two or more elements chemically combined in a set ratio. Ex:CO2 has a set ratio of 1:2, meaning for every one carbon atom there are two oxygen atoms. A) Element. B) Compound. C) Mixture. D) Salad. Show Answer Correct Answer: B) Compound. 9. A university plans to map all the genes on human chromosomes A) Basic research. B) Applied research. C) Technological research. D) None of above. Show Answer Correct Answer: A) Basic research. 10. Is 20 g greater than, less than, or equal to 2 kg? A) Greater than. B) Less than. C) Equal to. D) None of above. Show Answer Correct Answer: B) Less than. 11. A basketball has more mass than a golf ball because: A) The basketball takes up more space. B) The basketball contains more matter. C) The golf ball contains a different kind of matter. D) The golf ball has an indefinite composition. Show Answer Correct Answer: B) The basketball contains more matter. 12. A chemical property that refers to the energy released when a compound undergoes burning. A) Reactivity. B) Flammability. C) Chemical Stability. D) Heat of Combustion. Show Answer Correct Answer: D) Heat of Combustion. 13. This law states that energy cannot be created or destroyed, but it can change form. A) Endothermic reaction. B) Law of Conservation of EnergyLOCOE. C) Exothermic reaction. D) Law of Conservation of MatterLOCOM. Show Answer Correct Answer: B) Law of Conservation of EnergyLOCOE. 14. State change is always a ..... ..... A) Physical change. B) Physical property. C) Chemical change. D) Chemical property. Show Answer Correct Answer: A) Physical change. 15. Acetylene is burned in welding torches according to the following chemical reaction:2 C2H2 + 5 O2 $\rightarrow$ 4 CO2 + 2 H2OHow many oxygen (O) atoms are found in the reactants? A) 10. B) 5. C) 8. D) 2. Show Answer Correct Answer: A) 10. 16. What is the shape of H2O? A) Linear. B) Tetrahedral. C) Bent. D) Trigonal pyramidal. Show Answer Correct Answer: C) Bent. 17. Whichone of the following equations is correctly balanced? A) H2O $\rightarrow$3H2 + O2. B) H2 O $\rightarrow$ 2H2 + O2. C) 2H2O $\rightarrow$H2 + 4O2. D) 2H2O $\rightarrow$2H2 + O2. Show Answer Correct Answer: D) 2H2O $\rightarrow$2H2 + O2. 18. The property that describes how something looks (e.g. size, mass, texture, shape) and how it behaves around other substances (e.g. soluble, magnetic) A) Chemical. B) Physical. C) Appearance. D) Physique. Show Answer Correct Answer: B) Physical. 19. Mass Number = ..... A) No. of protons. B) No. of electrons. C) No. of neutrons. D) Protons + Neutrons. Show Answer Correct Answer: D) Protons + Neutrons. 20. Which of the following phase changes is exothermic? A) Melting. B) Freezing. C) Vaporization (evaporation). D) Sublimation. Show Answer Correct Answer: B) Freezing. ← PreviousNext →Related QuizzesScience QuizzesChemistry Quiz 1Chemistry Quiz 2Chemistry Quiz 3Chemistry Quiz 4Chemistry Quiz 5Chemistry Quiz 6Chemistry Quiz 7Chemistry Quiz 8Chemistry Quiz 9 🏠 Back to Homepage 📘 Download PDF Books 📕 Premium PDF Books