RRB Group D - Atoms and molecules Online Test (MCQ Quiz)

1. What is the basic unit of matter?

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

2. Who is credited with the development of the atomic theory?

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

3. Which subatomic particle has a positive charge?

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

4. What is the charge of an electron?

A) Positive B) Negative C) Neutral D) Variable

5. Which subatomic particle is found in the nucleus of an atom and has no charge?

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

6. The number of protons in an atom's nucleus determines its:

A) Mass Number B) Atomic Mass C) Atomic Number D) Isotopic Number

7. What is the term for atoms of the same element that have different numbers of neutrons?

A) Isotopes B) Isobars C) Isotones D) Ions

8. Carbon-12 and Carbon-14 are examples of:

A) Isobars B) Isotones C) Isomers D) Isotopes

9. What is the mass number of an atom?

A) Number of protons only B) Number of neutrons only C) Sum of protons and neutrons D) Sum of protons and electrons

10. An atom that has gained or lost electrons is called a(n):

A) Isotope B) Molecule C) Ion D) Radical

11. A positively charged ion is called a:

A) Anion B) Cation C) Neutron D) Proton

12. A negatively charged ion is called a(n):

A) Cation B) Anion C) Molecule D) Atom

13. What is a molecule?

A) A single atom B) Two or more atoms bonded together C) A charged atom D) The nucleus of an atom

14. Which of the following represents a molecule of water?

A) O2 B) CO2 C) H2O D) NaCl

15. What is the chemical symbol for oxygen?

A) Ox B) O C) Og D) Oy

16. What is the chemical symbol for sodium?

A) So B) Na C) Sn D) Sd

17. What is the atomic number of Carbon?

A) 4 B) 5 C) 6 D) 7

18. What is the atomic number of Hydrogen?

A) 0 B) 1 C) 2 D) 3

19. What is the atomic number of Helium?

A) 1 B) 2 C) 3 D) 4

20. How many atoms are in one molecule of Carbon Dioxide (CO2)?

A) 1 B) 2 C) 3 D) 4

21. How many atoms are in one molecule of Ozone (O3)?

A) 1 B) 2 C) 3 D) 4

22. The number of electrons in a neutral atom is equal to the number of:

A) Neutrons B) Protons C) Mass Number D) Nucleons

23. What is the unit used to express the relative atomic mass of an element?

A) Gram (g) B) Kilogram (kg) C) Atomic Mass Unit (amu) D) Mole

24. What is the relative atomic mass of Hydrogen?

A) 1.008 amu B) 12.011 amu C) 15.999 amu D) 55.845 amu

25. What is the relative atomic mass of Oxygen?

A) 1.008 amu B) 12.011 amu C) 15.999 amu D) 14.007 amu

26. What is the relative atomic mass of Carbon?

A) 1.008 amu B) 12.011 amu C) 15.999 amu D) 55.845 amu

27. What is the relative molecular mass of water (H2O)?

A) 18.015 amu B) 28.010 amu C) 32.000 amu D) 44.010 amu

28. What is the relative molecular mass of Carbon Dioxide (CO2)?

A) 18.015 amu B) 28.010 amu C) 32.000 amu D) 44.010 amu

29. What is Avogadro's number?

A) 6.022 x 10^20 B) 6.022 x 10^21 C) 6.022 x 10^22 D) 6.022 x 10^23

30. One mole of any substance contains Avogadro's number of particles. This is known as:

A) Law of Conservation of Mass B) Avogadro's Law C) Law of Definite Proportions D) Dalton's Law

31. What is the molar mass of a substance?

A) The mass of one atom in grams B) The mass of one molecule in grams C) The mass of one mole of a substance in grams D) The mass of a single proton in grams

32. What is the molar mass of water (H2O)?

A) 18.015 g/mol B) 28.010 g/mol C) 32.000 g/mol D) 44.010 g/mol

33. What is the molar mass of Carbon Dioxide (CO2)?

A) 18.015 g/mol B) 28.010 g/mol C) 32.000 g/mol D) 44.010 g/mol

34. The chemical formula for common salt is:

A) KCl B) Na2SO4 C) NaCl D) MgCl2

35. Which element has the symbol 'Fe'?

A) Fluorine B) Iron C) Phosphorus D) Fermium

36. Which element has the symbol 'K'?

A) Potassium B) Krypton C) Kilo D) Kelp

37. What is the electronic configuration of Sodium (Na) with atomic number 11?

A) 2, 8, 1 B) 2, 7, 2 C) 1, 8, 2 D) 8, 2, 1

38. What is the electronic configuration of Chlorine (Cl) with atomic number 17?

A) 2, 8, 7 B) 2, 7, 8 C) 1, 8, 8 D) 8, 7, 2

39. The law stating that a chemical compound always contains the same elements in the same proportion by mass is:

A) Law of Conservation of Mass B) Avogadro's Law C) Law of Definite Proportions D) Law of Multiple Proportions

40. Which law states that matter cannot be created or destroyed in a chemical reaction?

A) Law of Definite Proportions B) Law of Conservation of Mass C) Avogadro's Law D) Gay-Lussac's Law

41. What is the symbol for a neutral atom of Helium?

A) He+ B) He- C) He D) H2

42. What is the symbol for a sodium ion that has lost one electron?

A) Na- B) Na+ C) Na2+ D) Na

43. What is the symbol for a chloride ion that has gained one electron?

A) Cl+ B) Cl- C) Cl2- D) Cl

44. Which of the following is an example of a diatomic molecule?

A) O3 B) H2O C) N2 D) CO2

45. Which of the following is an example of a triatomic molecule?

A) H2 B) O2 C) H2O D) N2

46. The nucleus of an atom consists of:

A) Electrons and Neutrons B) Protons and Electrons C) Protons and Neutrons D) Electrons only

47. What is the charge of the nucleus of an atom?

A) Negative B) Positive C) Neutral D) Variable

48. Which scientist proposed the 'plum pudding' model of the atom?

A) Ernest Rutherford B) John Dalton C) J.J. Thomson D) Niels Bohr

49. Rutherford's gold foil experiment led to the discovery of the:

A) Electron B) Proton C) Neutron D) Atomic Nucleus

50. What is the primary role of electrons in chemical bonding?

A) To provide mass to the atom B) To determine the element's identity C) To participate in the formation of chemical bonds D) To stabilize the nucleus

Atoms and molecules - Online Test

Test Results