Nokea
Which type of bond involves sharing pairs of electrons?
- A. Ionic
- B. Covalent
- C. Both
- D. None of the above
Correct Answer: B
Rationale: In a covalent bond, atoms share pairs of electrons to achieve a stable electron configuration. This sharing of electrons leads to the formation of a strong bond between atoms. Ionic bonds, on the other hand, involve the transfer of electrons from one atom to another. Therefore, the correct answer is option B, Covalent, as it specifically describes the sharing of electron pairs, distinguishing it from ionic bonds where electron transfer occurs rather than electron sharing.
You may also like to solve these questions
What is the term for the number of protons in an atom?
- A. atomic identity
- B. atomic mass
- C. atomic weight
- D. atomic number
Correct Answer: D
Rationale: The term for the number of protons in an atom is the atomic number. The atomic number is a fundamental property of an element, representing the number of protons in an atom's nucleus. It serves as the unique identity of an element and determines its position on the periodic table and its chemical behavior. Atomic mass refers to the average mass of an atom, including protons, neutrons, and electrons, while atomic weight is the average weight of an element considering the abundance of its isotopes. 'Atomic identity' is not a standard term in chemistry to describe the number of protons in an atom, making option D, 'atomic number,' the correct answer.
Which statement is true regarding combination reactions?
- A. Involve only one reactant.
- B. Involve an element and an ionic compound.
- C. Form only one product.
- D. Require oxygen gas.
Correct Answer: C
Rationale: In a combination reaction, two or more substances combine to form a single product. This reaction type does not always involve only one reactant (choice A), an element and an ionic compound (choice B), or require oxygen gas (choice D). The true characteristic of combination reactions is that they form only one product, making choice C the correct answer.
Which of the following exhibits the most molecular interactions?
- A. Solid
- B. Liquid
- C. Gas
- D. None of the above
Correct Answer: A
Rationale: The correct answer is 'Solid.' In solids, molecules are closely packed, leading to strong intermolecular forces and the highest number of molecular interactions among the given options. This close proximity results in strong attractions between molecules, creating a high number of interactions. In contrast, liquids have weaker intermolecular forces due to more freedom of movement among molecules, leading to fewer interactions compared to solids. Gases have the least molecular interactions as their molecules are widely dispersed and have minimal attraction to each other, resulting in the lowest number of interactions.
What volume of silver metal will weigh exactly 2500.0 g? The density of silver is 10.5 g/cm³.
- A. 26250 cm³
- B. 238.1 cm³
- C. 0.0042 cm³
- D. None of the above
Correct Answer: B
Rationale: To determine the volume of silver, we use the formula: Volume = Mass / Density. Substituting the given values, Volume = 2500.0 g / 10.5 g/cm³ = 238.1 cm³. Therefore, the correct answer is 238.1 cm³, which represents the volume of silver metal weighing precisely 2500.0 g at a density of 10.5 g/cm³.
What is the density of iron when 28.5g of iron shot is added to a graduated cylinder containing 45.5mL of water, causing the water level to rise to the 49.1mL mark?
- A. 0.63 g/mL
- B. 7.92 g/mL
- C. 0.58 g/mL
- D. None of the above
Correct Answer: B
Rationale: To determine the density of iron, we use the formula: Density = Mass / Volume. The mass of the iron is given as 28.5g. The volume of water displaced by the iron is the final volume (49.1mL) minus the initial volume (45.5mL), resulting in 3.6mL. Therefore, the density of iron can be calculated by dividing the mass of iron (28.5g) by the volume of water displaced (3.6mL), giving us 7.92 g/mL. Therefore, choice B, 7.92 g/mL, is the correct answer.