NEET UG - Matter and its nature, Dalton's atomic theory, concept of atom molecule element and compound Online Test (MCQ Quiz)

1. Which of the following is a characteristic of matter?

A) It possesses mass and occupies space. B) It has only mass but no volume. C) It has volume but no mass. D) It neither has mass nor occupies space.

2. According to Dalton's atomic theory, atoms of a given element are:

A) Identical in all respects. B) Different from atoms of other elements. C) Able to be created or destroyed. D) Divisible into subatomic particles.

3. Dalton's atomic theory states that atoms combine in the ratio of small whole numbers to form:

A) Elements B) Molecules of compounds C) Atoms D) Ions

4. What is the fundamental unit of a chemical element?

A) Molecule B) Compound C) Atom D) Ion

5. Which of the following is an example of an element?

A) Water (H₂O) B) Salt (NaCl) C) Oxygen (O₂) D) Sugar (C₁₂H₂₂O₁₁)

6. A substance formed when two or more chemical elements are chemically bonded together is called a(n):

A) Element B) Atom C) Mixture D) Compound

7. Which of the following is a compound?

A) Gold (Au) B) Diamond (C) C) Ammonia (NH₃) D) Helium (He)

8. What is the smallest particle of an element that retains its chemical identity?

A) Molecule B) Proton C) Atom D) Electron

9. According to Dalton's atomic theory, atoms cannot be created or destroyed in a:

A) Physical process B) Chemical reaction C) Nuclear reaction D) Phase transition

10. Which term describes a combination of two or more substances that are not chemically bonded?

A) Element B) Compound C) Mixture D) Atom

11. Dalton's atomic theory was proposed in the year:

A) 1774 B) 1803 C) 1900 D) 1950

12. The law of definite proportions is consistent with which of the following concepts?

A) Elements are made of atoms. B) Atoms of a given element are identical. C) Compounds are formed by the chemical combination of elements. D) Atoms combine in simple whole number ratios.

13. Which of the following is NOT a postulate of Dalton's atomic theory?

A) Matter is composed of atoms. B) Atoms are indivisible. C) Atoms of different elements can be converted into one another. D) Atoms combine in simple whole number ratios.

14. A molecule is the smallest particle of a substance that:

A) Can exist independently and exhibits all the properties of the substance. B) Consists of only one type of atom. C) Can be chemically bonded with other atoms. D) Is a fundamental building block of matter.

15. Which of the following represents a molecule of a compound?

A) O₂ B) H₂ C) H₂O D) Fe

16. The basic building blocks of all matter are called:

A) Molecules B) Compounds C) Elements D) Atoms

17. Which of the following is an example of a diatomic element?

A) Ozone (O₃) B) Sulfur (S₈) C) Nitrogen (N₂) D) Phosphorus (P₄)

18. A substance that cannot be broken down into simpler substances by chemical means is called a(n):

A) Atom B) Molecule C) Compound D) Element

19. Dalton's atomic theory helped explain the laws of chemical combination, such as:

A) The law of conservation of mass and the law of definite proportions. B) The law of multiple proportions and the law of reciprocal proportions. C) Both A and B. D) None of the above.

20. Which of the following is NOT considered matter?

A) Air B) Light C) Water D) Rock

21. According to Dalton, atoms of different elements differ in:

A) Mass B) Chemical properties C) Both mass and chemical properties D) Number of protons

22. Which of the following is a polyatomic molecule?

A) H₂ B) O₂ C) N₂ D) O₃

23. The concept of an atom was first proposed by:

A) John Dalton B) Antoine Lavoisier C) Democritus D) J.J. Thomson

24. A compound's properties are typically __________ than those of its constituent elements.

A) Similar B) Identical C) Different D) The same

25. Which of the following is an example of a pure substance?

A) Air B) Seawater C) Sugar D) Milk

26. Dalton's atomic theory suggested that atoms of one element could be transformed into atoms of another element during:

A) Physical changes B) Chemical reactions C) Phase transitions D) None of the above

27. What is the fundamental particle of a compound that retains its chemical properties?

A) Atom B) Element C) Molecule D) Ion

28. Which of the following is a characteristic of a mixture?

A) Fixed composition B) Components are chemically bonded C) Components retain their individual properties D) Can only be separated by chemical means

29. The smallest unit of matter that exhibits the properties of an element is:

A) Proton B) Neutron C) Electron D) Atom

30. Which of the following substances is an element?

A) Carbon dioxide (CO₂) B) Methane (CH₄) C) Iron (Fe) D) Water (H₂O)

31. Dalton's atomic theory proposed that atoms are:

A) Infinitely divisible B) Electrically charged particles C) Indivisible and indestructible D) Composed of protons, neutrons, and electrons

32. Which of the following is an example of a compound?

A) Oxygen gas (O₂) B) Hydrogen gas (H₂) C) Sodium chloride (NaCl) D) Nitrogen gas (N₂)

33. The concept of a molecule was developed to explain the behavior of:

A) Elements B) Compounds C) Both elements and compounds D) Atoms

34. According to Dalton's atomic theory, chemical reactions involve:

A) The creation of new atoms. B) The destruction of existing atoms. C) The rearrangement, combination, or separation of atoms. D) The conversion of one element into another.

35. Which of the following has a definite chemical composition?

A) Air B) Soil C) Pure water D) Brass

36. The smallest particle of an element that can exist independently is a(n):

A) Atom B) Molecule C) Compound D) Ion

37. Which of the following is a molecular element?

A) Sodium (Na) B) Sulfur (S) C) Copper (Cu) D) Helium (He)

38. Dalton's atomic theory was a significant advancement because it provided a quantitative basis for understanding:

A) The structure of the atom. B) The nature of chemical bonding. C) The laws of chemical combination. D) The states of matter.

39. What is the basic unit of a compound?

A) Atom B) Element C) Molecule D) Proton

40. Which of the following is an example of matter?

A) Sound B) Heat C) Electricity D) Smoke

41. According to Dalton's atomic theory, atoms of the same element are:

A) Identical in mass and properties. B) Different in mass but similar in properties. C) Identical in mass but different in properties. D) Different in mass and properties.

42. A substance composed of two or more elements chemically combined in a fixed ratio is a(n):

A) Mixture B) Element C) Compound D) Solution

43. Which of the following is a diatomic molecule?

A) H₂O B) CO₂ C) O₃ D) HCl

44. Dalton's atomic theory states that atoms of different elements combine to form:

A) Atoms of the same element B) Molecules of elements C) Molecules of compounds D) Ions

45. Which of the following is an example of an element that exists as discrete atoms?

A) Oxygen (O₂) B) Nitrogen (N₂) C) Helium (He) D) Hydrogen (H₂)

46. The smallest particle of matter that retains the chemical properties of a substance is called:

A) Atom B) Molecule C) Compound D) Element

47. Which of the following is NOT a postulate of Dalton's atomic theory regarding atoms?

A) Atoms are the smallest particles of an element. B) Atoms of different elements have different properties. C) Atoms can be divided into subatomic particles. D) Atoms combine in simple whole number ratios to form compounds.

48. A substance that consists of only one type of atom is called a(n):

A) Compound B) Mixture C) Element D) Molecule

49. The basic unit of a chemical element is the:

A) Molecule B) Compound C) Atom D) Ion

50. Dalton's atomic theory considered atoms to be:

A) Electrically neutral entities B) Charged particles C) Energy packets D) Vibrating strings

Matter and its nature, Dalton's atomic theory, concept of atom molecule element and compound - Online Test

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