On the periodic table, elements in the same row are characterized by:
- A. an increasing number of neutrons from left to right.
- B. a decreasing number of neutrons from left to right.
- C. an increasing number of protons from left to right.
- D. a decreasing number of protons from left to right.
Correct Answer & Rationale
Correct Answer: C
Elements in the same row, or period, of the periodic table are arranged by increasing atomic number, which corresponds to the number of protons. Therefore, as you move from left to right across a row, the number of protons increases. Option A is incorrect because the number of neutrons does not consistently increase across a row; it varies based on the specific isotopes of each element. Option B is also incorrect for the same reason, as neutrons can vary independently of proton count. Option D is incorrect since it suggests a decrease in protons, which contradicts the fundamental organization of the periodic table.
Elements in the same row, or period, of the periodic table are arranged by increasing atomic number, which corresponds to the number of protons. Therefore, as you move from left to right across a row, the number of protons increases. Option A is incorrect because the number of neutrons does not consistently increase across a row; it varies based on the specific isotopes of each element. Option B is also incorrect for the same reason, as neutrons can vary independently of proton count. Option D is incorrect since it suggests a decrease in protons, which contradicts the fundamental organization of the periodic table.
Other Related Questions
A metal spoon that heats up while sitting in a bowl of hot soup is an example of heat transfer by:
- A. conduction
- B. convection
- C. radiation
- D. diffusion
Correct Answer & Rationale
Correct Answer: A
Heat transfer occurs through different mechanisms, and in this scenario, the metal spoon absorbs heat from the hot soup primarily through conduction. Conduction involves direct contact, where heat moves from the hot soup molecules to the cooler spoon molecules. Convection, option B, refers to heat transfer through fluid movement, which does not apply here since the spoon is not moving the soup. Radiation, option C, involves heat transfer through electromagnetic waves, which is not relevant in this case as there is no significant radiation involved. Lastly, diffusion, option D, pertains to the movement of particles from areas of high concentration to low concentration and is unrelated to heat transfer in this context.
Heat transfer occurs through different mechanisms, and in this scenario, the metal spoon absorbs heat from the hot soup primarily through conduction. Conduction involves direct contact, where heat moves from the hot soup molecules to the cooler spoon molecules. Convection, option B, refers to heat transfer through fluid movement, which does not apply here since the spoon is not moving the soup. Radiation, option C, involves heat transfer through electromagnetic waves, which is not relevant in this case as there is no significant radiation involved. Lastly, diffusion, option D, pertains to the movement of particles from areas of high concentration to low concentration and is unrelated to heat transfer in this context.
The pitch of a sound is related to which of the following properties of a sound wave?
- A. Speed
- B. Frequency
- C. Amplitude
- D. Energy
Correct Answer & Rationale
Correct Answer: B
The pitch of a sound is directly related to its frequency, which refers to how many sound wave cycles occur in one second. Higher frequencies produce higher pitches, while lower frequencies result in lower pitches. Option A, speed, refers to how fast sound travels through a medium but does not affect pitch. Option C, amplitude, relates to the loudness or intensity of a sound rather than its pitch. Option D, energy, is associated with the overall power of the sound wave but does not determine pitch. Thus, frequency is the key property that defines the pitch of a sound.
The pitch of a sound is directly related to its frequency, which refers to how many sound wave cycles occur in one second. Higher frequencies produce higher pitches, while lower frequencies result in lower pitches. Option A, speed, refers to how fast sound travels through a medium but does not affect pitch. Option C, amplitude, relates to the loudness or intensity of a sound rather than its pitch. Option D, energy, is associated with the overall power of the sound wave but does not determine pitch. Thus, frequency is the key property that defines the pitch of a sound.
Which of the following is true about the nucleus of an atom?
- A. The nucleus has a negative charge.
- B. The nucleus is neutral with no charge.
- C. The electrons and protons are located in the nucleus.
- D. The neutrons and protons are located in the nucleus.
Correct Answer & Rationale
Correct Answer: D
The nucleus of an atom is composed of protons and neutrons, making option D accurate. Protons carry a positive charge, while neutrons are neutral, contributing to the overall positive charge of the nucleus. Option A is incorrect because the nucleus does not have a negative charge; it is positively charged due to protons. Option B is also wrong, as the nucleus is not neutral; it has a positive charge from the protons. Lastly, option C is misleading because electrons are located outside the nucleus in electron shells, not within it.
The nucleus of an atom is composed of protons and neutrons, making option D accurate. Protons carry a positive charge, while neutrons are neutral, contributing to the overall positive charge of the nucleus. Option A is incorrect because the nucleus does not have a negative charge; it is positively charged due to protons. Option B is also wrong, as the nucleus is not neutral; it has a positive charge from the protons. Lastly, option C is misleading because electrons are located outside the nucleus in electron shells, not within it.
Which of the following is a true statement about sodium chloride (NaCl)?
- A. It is a gas at room temperature.
- B. It is a compound formed from two elements.
- C. It is a mixture formed from two different compounds.
- D. It is an element that is unstable and reactive.
Correct Answer & Rationale
Correct Answer: B
Sodium chloride (NaCl) is indeed a compound formed from two elements: sodium (Na) and chlorine (Cl), which combine in a fixed ratio through ionic bonding. Option A is incorrect; NaCl is a solid at room temperature, not a gas. Option C misrepresents NaCl as a mixture, but it is a pure compound, not formed from different compounds. Option D inaccurately describes NaCl as an element; it is a stable compound, not unstable or reactive under normal conditions. Thus, option B accurately reflects the nature of sodium chloride.
Sodium chloride (NaCl) is indeed a compound formed from two elements: sodium (Na) and chlorine (Cl), which combine in a fixed ratio through ionic bonding. Option A is incorrect; NaCl is a solid at room temperature, not a gas. Option C misrepresents NaCl as a mixture, but it is a pure compound, not formed from different compounds. Option D inaccurately describes NaCl as an element; it is a stable compound, not unstable or reactive under normal conditions. Thus, option B accurately reflects the nature of sodium chloride.