Atoms and molecules Knowledge-Based Practice

Questions

1. 1.

   What structural feature allows an atom to achieve maximum chemical stability and resist forming bonds to produce molecules?

   • A) Having an equal number of protons and neutrons within its nucleus
   • B) Possessing an electrical charge equal to the mass number of the atom
   • C) Possessing a completely filled outermost valence electron shell
   • D) Retaining an equal number of electron shells as neighboring atoms
2. 2.

   Which statement accurately distinguishes a molecule of an element from a molecule of a compound?

   • A) A molecule of an element is held together by ionic bonds, whereas a molecule of a compound is held together exclusively by covalent bonds.
   • B) A molecule of an element consists of only one kind of atom, whereas a molecule of a compound contains two or more different kinds of atoms chemically combined.
   • C) A molecule of an element cannot participate in chemical reactions, whereas a molecule of a compound readily undergoes chemical transformations.
   • D) A molecule of an element contains an unequal number of protons and electrons, whereas a molecule of a compound always maintains electrical neutrality.
3. 3.

   When atoms of different elements chemically combine to form a compound, how do the properties of the resulting substance compare to those of its constituent elements?

   • A) The compound retains an arithmetic average of the chemical reactivities and physical states of its component elements.
   • B) The compound exhibits novel emergent properties that are distinct from the characteristics of its individual component elements.
   • C) The compound displays only the physical and chemical behaviors of the most abundant element present in its structure.
   • D) The compound maintains the separate chemical identities of its elements because their atomic nuclei merge into a single entity.
4. 4.

   Which subatomic particles are directly shared, gained, or lost when atoms interact to form molecules?

   • A) Valence electrons located in the outermost electron shell
   • B) Neutrons located within the central atomic nucleus
   • C) Protons found in the atomic nucleus that determine atomic number
   • D) Core electrons occupying the completely filled innermost electron shell
5. 5.

   Which of the following statements best describes the relationship between atoms and molecules in biological systems?

   • A) Molecules are chemical structures composed of two or more atoms held together by covalent bonds.
   • B) Atoms are complex structures formed when multiple molecules chemically combine in fixed ratios.
   • C) Molecules are single subatomic particles that exist without containing any intact atoms.
   • D) Atoms and molecules are identical units that differ only in their physical state of matter.

Answers and step-by-step solutions appear after you finish the test.