What phenomenon explains the bending of light as it passes around an obstacle or through an aperture?

Correct Answer: C

Rationale: Diffraction is the phenomenon that explains the bending of light as it passes around an obstacle or through an aperture. When light encounters an obstacle or passes through an aperture, it diffracts, causing it to bend around the edges. Refraction, on the other hand, occurs when light passes from one medium to another, causing it to change direction. Reflection involves the bouncing back of light rays from a surface, and dispersion is the separation of light into its different colors. Therefore, the correct answer is C, as diffraction specifically addresses the bending of light as it interacts with obstacles or apertures, unlike the other choices that describe different optical phenomena.

Correct Answer: A

Rationale: The element with atomic number 26 and mass number 56 corresponds to Iron (Fe). Iron has 26 protons, which aligns with the given atomic number, and Fe-56 has 26 neutrons, which aligns with the given mass number. This confirms that Iron (Fe) is the correct answer. Cobalt (Co), Nickel (Ni), and Manganese (Mn) have different atomic numbers and mass numbers, so they are not the correct choices in this scenario.

Correct Answer: A

Rationale: The correct answer is A: Covalent bond. In a covalent bond, atoms share electrons, leading to the creation of a strong attraction that holds them together. This type of bond is characterized by the sharing of electron pairs between atoms, resulting in the formation of molecules. Choice B, Ionic bond, involves the transfer of electrons from one atom to another, creating charged ions that attract each other. Choice C, Metallic bond, refers to the sharing of electrons among a sea of delocalized electrons in a metal structure. Choice D, Hydrogen bond, is a weak electrostatic attraction between a hydrogen atom and an electronegative atom like oxygen or nitrogen, not involving the sharing of electrons.

Correct Answer: B

Rationale: In a covalent bond, the shared electrons spend more time closer to the more electronegative atom. Electronegativity is the ability of an atom to attract electrons in a chemical bond. The more electronegative atom exerts a stronger pull on the shared electrons, causing them to be closer to that atom. Choice A is incorrect because in a covalent bond, electrons are shared, not completely transferred. Choice C is incorrect as the shared electrons are not equidistant but are closer to one atom due to electronegativity differences. Choice D is incorrect because shared electrons play a significant role in determining the bond strength by the strength of the bond formed through electron sharing.

Correct Answer: B

Rationale: The group number of an element on the periodic table often indicates the typical ionic charge it will form. Elements in the same group tend to have similar chemical properties, including the tendency to gain or lose electrons to achieve a stable electron configuration. This predictable pattern allows us to anticipate the charge of an ion formed by an element based on its position in the periodic table. Choices A, C, and D are incorrect because predicting the charge of an ion is primarily based on the element's group number, which reflects its valence electrons and typical ionic charge. Atomic weight (Choice A) and period number (Choice C) do not directly correlate with the ionic charge prediction, and analyzing the element's position within the group (Choice D) is less relevant than identifying the group number itself.