Periodic Trends — Set 4
Chemistry · आवर्ती प्रवृत्तियां · Questions 31–40 of 50
Which of the following is a characteristic of Group 17 elements?
Correct Answer: C. Strong oxidizing agents
Group 17 elements, known as halogens, are very strong oxidizing agents. They readily gain one electron to complete their octet. Fluorine is the strongest oxidizing agent among them.
What is the name of the elements from atomic number 58 to 71?
Correct Answer: A. Lanthanides
Elements from 58 to 71 are called Lanthanides. They follow the element Lanthanum in the periodic table. They are often referred to as rare earth elements.
The tendency of an atom to attract a shared pair of electrons is called?
Correct Answer: A. Electronegativity
Electronegativity is the measure of an atom's ability to pull electrons in a bond. It generally increases across a period and decreases down a group. It is a dimensionless quantity often measured on the Pauling scale.
Which element is commonly used as the reference for modern atomic mass units?
Correct Answer: A. Carbon-12
Carbon-12 is the standard isotope used to define the atomic mass unit. One atomic mass unit is exactly 1/12th the mass of a Carbon-12 atom. This scale allows scientists to compare relative masses of all elements.
Which group of elements shows the most stable electronic configurations?
Correct Answer: B. Group 18
Group 18 elements have a complete octet or duplet in their outer shell. This makes them chemically stable and reluctant to form bonds. They are found as monoatomic gases in nature.
Which of the following elements has the lowest first ionization energy?
Correct Answer: A. Cesium
Cesium has a very low ionization energy because its outer electron is far from the nucleus. It is easily lost, making Cesium highly reactive. This property is utilized in atomic clocks.
In the modern periodic table, how many periods and groups are there?
Correct Answer: A. 7 periods, 18 groups
The modern periodic table consists of 7 horizontal periods and 18 vertical groups. Each period represents the highest energy level occupied by electrons. This structure organizes elements by increasing atomic number.
Which of the following is a radioactive noble gas?
Correct Answer: C. Radon
Radon is a radioactive noble gas that occurs naturally from the decay of uranium. It can accumulate in buildings and pose a health risk. It is the heaviest of the naturally occurring noble gases.
Which block of elements includes the transuranium elements?
Correct Answer: B. f-block
Transuranium elements are those with atomic numbers greater than 92 (Uranium). They belong to the Actinide series in the f-block. Almost all of these elements are synthetic and radioactive.
Which element is found in all organic compounds?
Correct Answer: A. Carbon
Carbon is the essential element for all organic life forms. It has the unique ability to form long chains and rings through catenation. This versatility leads to millions of known organic molecules.