Chemistry Basic Concepts Practice Questions

1. Who proposed the atomic theory?

2. What is the atomic number of Carbon?

3. Which element has the highest electronegativity?

4. What is the pH of pure water at 25°C?

5. Which gas is known as laughing gas?

6. What is the chemical formula of common salt?

7. Which element is most abundant in Earth’s crust?

8. What is the valency of carbon?

9. Which acid is present in lemon?

10. What is the chemical symbol for gold?

11. Which gas is used in balloons to make them float?

12. What is the hardest natural substance?

13. Which element is liquid at room temperature?

14. What is the chemical formula for water?

15. Which gas is essential for photosynthesis?

16. What is the pH range of acids?

17. Which metal is known as quicksilver?

18. What is the main component of natural gas?

19. Which element is essential for hemoglobin?

20. What type of bond is formed by sharing electrons?

21. Which acid is present in vinegar?

22. What is the chemical formula for baking soda?

23. Which gas causes greenhouse effect?

24. What is the atomic mass of hydrogen?

25. Which element is used in pencils?

26. What is the chemical name for lime water?

27. Which metal is most reactive?

28. What is the chemical formula for ammonia?

29. Which element has the symbol ‘Fe’?

30. What is the process of converting liquid to gas called?

31. Which acid is found in ant sting?

32. What is the chemical formula for glucose?

33. Which gas is used for ripening fruits?

34. What is the valency of oxygen?

35. Which element is a noble gas?

36. What is the chemical name for bleaching powder?

37. Which metal is used in thermometers?

38. What is the chemical formula for sulfuric acid?

39. Which element is essential for bones and teeth?

40. What is dry ice?

41. Which gas is produced during photosynthesis?

42. What is the chemical symbol for sodium?

43. Which type of reaction absorbs heat?

44. What is the chemical formula for washing soda?

45. Which element is used in making stainless steel?

46. What is the chemical name for plaster of Paris?

47. Which gas is used in fire extinguishers?

48. What is the chemical formula for methane?

49. Which element is found in all organic compounds?