Atoms and molecules - Question Bank

1. The octet rule states that atoms tend to gain, lose, or share electrons to achieve a full outer shell of how many electrons?
A) 2
B) 4
C) 6
D) 8
2. What are valence electrons?
A) Electrons in the innermost shell
B) Electrons in the outermost shell
C) All electrons in an atom
D) Electrons involved in nuclear reactions
3. 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
4. Rutherford's gold foil experiment led to the discovery of the:
A) Electron
B) Proton
C) Neutron
D) Atomic Nucleus
5. Which scientist proposed the 'plum pudding' model of the atom?
A) Ernest Rutherford
B) John Dalton
C) J.J. Thomson
D) Niels Bohr
6. What is the charge of the nucleus of an atom?
A) Negative
B) Positive
C) Neutral
D) Variable
7. The nucleus of an atom consists of:
A) Electrons and Neutrons
B) Protons and Electrons
C) Protons and Neutrons
D) Electrons only
8. Which of the following is an example of a triatomic molecule?
A) H2
B) O2
C) H2O
D) N2
9. Which of the following is an example of a diatomic molecule?
A) O3
B) H2O
C) N2
D) CO2
10. What is the symbol for a chloride ion that has gained one electron?
A) Cl+
B) Cl-
C) Cl2-
D) Cl
11. What is the symbol for a sodium ion that has lost one electron?
A) Na-
B) Na+
C) Na2+
D) Na
12. What is the symbol for a neutral atom of Helium?
A) He+
B) He-
C) He
D) H2
13. 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
14. 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
15. 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
16. 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
17. Which element has the symbol 'K'?
A) Potassium
B) Krypton
C) Kilo
D) Kelp
18. Which element has the symbol 'Fe'?
A) Fluorine
B) Iron
C) Phosphorus
D) Fermium
19. The chemical formula for common salt is:
A) KCl
B) Na2SO4
C) NaCl
D) MgCl2
20. 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
21. 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
22. 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
23. 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
24. 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
25. 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
26. 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
27. What is the relative atomic mass of Carbon?
A) 1.008 amu
B) 12.011 amu
C) 15.999 amu
D) 55.845 amu
28. What is the relative atomic mass of Oxygen?
A) 1.008 amu
B) 12.011 amu
C) 15.999 amu
D) 14.007 amu
29. What is the relative atomic mass of Hydrogen?
A) 1.008 amu
B) 12.011 amu
C) 15.999 amu
D) 55.845 amu
30. 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
31. The number of electrons in a neutral atom is equal to the number of:
A) Neutrons
B) Protons
C) Mass Number
D) Nucleons
32. How many atoms are in one molecule of Ozone (O3)?
A) 1
B) 2
C) 3
D) 4
33. How many atoms are in one molecule of Carbon Dioxide (CO2)?
A) 1
B) 2
C) 3
D) 4
34. What is the atomic number of Helium?
A) 1
B) 2
C) 3
D) 4
35. What is the atomic number of Hydrogen?
A) 0
B) 1
C) 2
D) 3
36. What is the atomic number of Carbon?
A) 4
B) 5
C) 6
D) 7
37. What is the chemical symbol for sodium?
A) So
B) Na
C) Sn
D) Sd
38. What is the chemical symbol for oxygen?
A) Ox
B) O
C) Og
D) Oy
39. Which of the following represents a molecule of water?
A) O2
B) CO2
C) H2O
D) NaCl
40. 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
41. A negatively charged ion is called a(n):
A) Cation
B) Anion
C) Molecule
D) Atom
42. A positively charged ion is called a:
A) Anion
B) Cation
C) Neutron
D) Proton
43. An atom that has gained or lost electrons is called a(n):
A) Isotope
B) Molecule
C) Ion
D) Radical
44. 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
45. Carbon-12 and Carbon-14 are examples of:
A) Isobars
B) Isotones
C) Isomers
D) Isotopes
46. What is the term for atoms of the same element that have different numbers of neutrons?
A) Isotopes
B) Isobars
C) Isotones
D) Ions
47. The number of protons in an atom's nucleus determines its:
A) Mass Number
B) Atomic Mass
C) Atomic Number
D) Isotopic Number
48. Which subatomic particle is found in the nucleus of an atom and has no charge?
A) Proton
B) Electron
C) Neutron
D) Positron
49. What is the charge of an electron?
A) Positive
B) Negative
C) Neutral
D) Variable
50. Which subatomic particle has a positive charge?
A) Electron
B) Neutron
C) Proton
D) Photon
All Question Banks
E-Book Atoms and molecules One Line Questions Atoms and molecules Online Test Atoms and molecules