Periodic Trends — Set 5
Chemistry · आवर्ती प्रवृत्तियां · Questions 41–50 of 50
The reactivity of metals __________ as we move down Group 1.?
Correct Answer: A. Increases
Reactivity increases down Group 1 because the outer electron is further from the nucleus. This makes it easier for the atom to lose that electron during a reaction. Potassium is significantly more reactive than Lithium.
Which group contains the alkaline earth metals?
Correct Answer: B. Group 2
Group 2 elements are known as alkaline earth metals. This group includes Beryllium, Magnesium, Calcium, Strontium, Barium, and Radium. They are shiny, silvery-white metals.
Which scientist discovered the existence of Noble Gases?
Correct Answer: C. William Ramsay
Sir William Ramsay was responsible for discovering the noble gases on Earth. He identified Helium, Neon, Argon, Krypton, and Xenon. He was awarded the Nobel Prize in Chemistry for this work.
The diagonal relationship is primarily caused by?
Correct Answer: C. Similar ionic sizes
Similar ionic sizes and charge densities lead to diagonal relationships. This causes elements like Beryllium and Aluminum to behave similarly. It is a unique feature observed in the first two periods.
Which element is used as a standard for high-temperature superconductors?
Correct Answer: B. Yttrium
Yttrium is a key component in the production of high-temperature superconductors. It is often used in the form of Yttrium Barium Copper Oxide. This material can conduct electricity without resistance at liquid nitrogen temperatures.
Which property decreases down a group but increases across a period?
Correct Answer: A. Ionization Energy
Ionization energy increases across a period and decreases down a group. Higher nuclear charge across a period makes it harder to remove electrons. Conversely, increasing shells down a group make electron removal easier.
Which element has the highest density at room temperature?
Correct Answer: A. Osmium
Osmium is the densest naturally occurring element. It has a density of approximately 22.59 g/cm³. It is a hard, brittle transition metal in the platinum group.
The valence of an element is determined by the number of?
Correct Answer: D. Outer electrons
Valence is determined by the number of electrons in the outermost shell. These electrons are involved in forming chemical bonds. Elements in the same group usually have the same valency.
Electronegativity generally increases across a period from?
Correct Answer: A. Left to right
Electronegativity increases from left to right across a period because atomic size decreases and nuclear charge increases, making atoms attract bonding electrons more strongly. Fluorine has the highest electronegativity (3.98).
Which of the following elements has the highest ionization energy?
Correct Answer: B. Helium
The correct answer is Helium. Helium has the highest ionization energy (2372 kJ/mol) among all elements because of its very small size and completely filled 1s orbital. Noble gases generally have very high ionization energies. This topic is frequently tested in competitive examinations such as RRB NTPC, SSC, and UPSC.