TRB PG Assistant - Structure of atoms, molecules, bonds Online Test (MCQ Quiz)

1. What subatomic particle carries a positive electrical charge?

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

2. Which subatomic particle has no electrical charge?

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

3. The atomic number of an element is determined by the number of:

A) Neutrons B) Electrons C) Protons D) Isotopes

4. What term describes atoms of the same element with different numbers of neutrons?

A) Isomers B) Ions C) Isotopes D) Allotropes

5. A molecule is formed when two or more atoms are joined by what type of bond?

A) Ionic bond B) Covalent bond C) Metallic bond D) Hydrogen bond

6. Which type of bond involves the transfer of electrons from one atom to another?

A) Covalent bond B) Ionic bond C) Polar covalent bond D) Nonpolar covalent bond

7. In a covalent bond, atoms:

A) Share electrons B) Lose electrons C) Gain electrons D) Exchange ions

8. What is the primary force that holds atoms together in a chemical bond?

A) Gravitational force B) Electromagnetic force C) Strong nuclear force D) Weak nuclear force

9. An atom that gains or loses electrons becomes an ion, which carries an electrical charge. True or False?

A) True B) False C) Depends on the element D) Only if it gains electrons

10. What is a cation?

A) A negatively charged ion B) A positively charged ion C) A neutral atom D) A molecule with an odd number of electrons

11. What is an anion?

A) A positively charged ion B) A neutral atom C) A negatively charged ion D) An atom with no neutrons

12. The bond formed between a metal and a nonmetal is typically:

A) Covalent B) Ionic C) Metallic D) Hydrogen

13. The bond formed between two nonmetals is typically:

A) Ionic B) Metallic C) Covalent D) Van der Waals

14. A polar covalent bond occurs when electrons are shared:

A) Equally between atoms B) Unequally between atoms C) Completely transferred from one atom to another D) Between ions

15. A nonpolar covalent bond occurs when electrons are shared:

A) Unequally between atoms B) Completely transferred from one atom to another C) Equally between atoms D) Between charged particles

16. Which of the following is an example of a molecule?

A) Na+ B) Cl- C) H2O D) Mg

17. What is the most abundant element in the universe?

A) Oxygen B) Carbon C) Helium D) Hydrogen

18. What is the atomic symbol for oxygen?

A) O2 B) Ox C) O D) Og

19. What is the chemical formula for water?

A) HO2 B) H2O C) O2H D) OH

20. Which element has the atomic number 6?

A) Nitrogen B) Carbon C) Boron D) Silicon

21. The mass number of an atom is the sum of the number of protons and:

A) Electrons B) Neutrons C) Isotopes D) Ions

22. What is the term for the energy required to remove an electron from an atom?

A) Electron affinity B) Ionization energy C) Electronegativity D) Bond energy

23. Which of the following is a noble gas?

A) Fluorine B) Neon C) Sodium D) Chlorine

24. What is the primary type of bond found in a diamond crystal (a form of carbon)?

A) Ionic bond B) Metallic bond C) Hydrogen bond D) Covalent bond

25. The attraction between oppositely charged ions is called an:

A) Covalent bond B) Metallic bond C) Ionic bond D) Hydrogen bond

26. What is the valence shell of an atom?

A) The innermost electron shell B) The outermost electron shell C) The nucleus of the atom D) The shell containing the most electrons

27. Atoms tend to gain, lose, or share electrons to achieve a stable electron configuration, often resembling that of:

A) Alkali metals B) Halogens C) Noble gases D) Transition metals

28. Which element has the chemical symbol 'Fe'?

A) Fluorine B) Iron C) Gold D) Silver

29. What is a double covalent bond?

A) Sharing of two electrons between two atoms B) Sharing of four electrons between two atoms C) Transfer of two electrons between two atoms D) Sharing of one electron between two atoms

30. Which of the following has the highest electronegativity?

A) Carbon B) Nitrogen C) Oxygen D) Fluorine

31. What type of bond is responsible for holding the two strands of a DNA molecule together?

A) Covalent bonds B) Ionic bonds C) Hydrogen bonds D) Metallic bonds

32. A chemical reaction in which electrons are transferred from one species to another is called a(n):

A) Acid-base reaction B) Precipitation reaction C) Redox reaction D) Combustion reaction

33. What is the atomic number of Helium?

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

34. Which of the following is a diatomic molecule?

A) Ozone (O3) B) Methane (CH4) C) Nitrogen (N2) D) Carbon Dioxide (CO2)

35. What is the process by which an atom or molecule gains electrons?

A) Oxidation B) Reduction C) Ionization D) Dissociation

36. What is the process by which an atom or molecule loses electrons?

A) Reduction B) Ionization C) Oxidation D) Neutralization

37. Which element is in Group 1 (alkali metals) of the periodic table?

A) Calcium B) Potassium C) Magnesium D) Aluminum

38. What is the charge of a neutron?

A) +1 B) -1 C) 0 D) Variable

39. The number of protons in an atom's nucleus is equal to its:

A) Mass number B) Atomic mass C) Atomic number D) Number of neutrons

40. What is a molecule composed of atoms of only one element called?

A) Compound B) Element C) Isotope D) Polymer

41. Which of the following is a compound?

A) O2 B) N2 C) CO2 D) He

42. What force holds the nucleus of an atom together?

A) Electromagnetic force B) Weak nuclear force C) Strong nuclear force D) Gravitational force

43. When an atom loses an electron, it becomes:

A) An anion with a negative charge B) A cation with a positive charge C) A neutral ion D) An isotope

44. Which type of bond is typically found in metals?

A) Ionic bond B) Covalent bond C) Metallic bond D) Hydrogen bond

45. What is the chemical symbol for sodium?

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

46. The octet rule states that atoms tend to achieve how many electrons in their outermost shell for stability?

A) Two B) Four C) Six D) Eight

47. What is the atomic number of Carbon?

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

48. Which of the following is NOT a type of chemical bond?

A) Ionic bond B) Covalent bond C) Hydrogen bond D) Gravitational bond

49. What is the primary difference between an atom and an ion?

A) Number of neutrons B) Number of protons C) Electrical charge D) Atomic mass

50. The molecule H2SO4 is known as:

A) Hydrochloric acid B) Sulfuric acid C) Nitric acid D) Acetic acid

Structure of atoms, molecules, bonds - Online Test

Test Results