CBSE Class 11 (Science) Classification of Elements — practice questions
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Practice CBSE Class 11 (Science) Classification of Elements in the app →According to VSEPR theory, the shape of a molecule is determined byThe hybridisation of carbon in methane (CH₄) isWhich molecule is non-polar despite having polar bonds?The bond order of the oxygen molecule O₂ (by molecular orbital theory) isA coordinate (dative) bond differs from a normal covalent bond in thatWhich species has sp hybridisation on the central atom?As bond order increases, bond lengthAn ionic bond forms byThe shape of NH₃ is pyramidal rather than planar becauseWhich has the highest dipole moment?Among the following, which is paramagnetic?Formal charge on an atom = As per your syllabus, the MODERN periodic law (post-Moseley 1913) states that properties of elements are a perAs per your syllabus, the IUPAC system numbers the groups in the modern table from which range, replacing the As per your syllabus, in IUPAC systematic nomenclature for Z > 100, what are the digit roots for 1, 2 and 0 reAs per your syllabus, the IUPAC systematic name + symbol for the element with atomic number 120 are which?As per your syllabus, the IUPAC OFFICIAL name + symbol for Z = 104 is which?As per your syllabus, the FIRST IONISATION ENTHALPY of an element X represents which process?As per your syllabus, the ELECTRON GAIN ENTHALPY ΔₑgH represents enthalpy change for which reaction?As per your syllabus, predicting the formula formed by SILICON (Group 14) and BROMINE (Group 17) gives which cRemoving an electron from a neutral atom produces a:Adding an electron to a neutral atom produces an:Ionic radii are estimated by measuring distances in:Ionic radii generally follow the same trend as the:A cation is smaller than its parent atom because it has fewer:An anion is larger than its parent atom because of increased:Species with the same number of electrons are called:Among isoelectronic species, a larger nuclear charge gives a radius:First ionisation enthalpy generally increases across a:First ionisation enthalpy generally decreases down a:The first ionisation enthalpy of boron against beryllium is:Within the same principal level, the more tightly held electron is the:The first ionisation enthalpy of oxygen against nitrogen is:In a nitrogen atom the three 2p electrons occupy orbitals that are:The pull of an atom on shared electrons in a bond is called:Electronegativity, unlike ionisation enthalpy, is:The electronegativity of an element is described as:Electronegativity helps in predicting the nature of the:Atomic size generally decreases as one moves across a:Atomic radius increases regularly as one descends a:Which ion is smaller than its parent atom?Isoelectronic species differ from one another in their:Who proposed the Law of Triads in 1829?Newlands' Law of Octaves held good only for elements up to which element?Newlands was later honoured for his Law of Octaves with which award in 1887?Which chemist plotted atomic volume against atomic weight and found a repeating pattern in 1869?Mendeleev placed iodine in the halogen group despite its lower atomic weight than which element?Mendeleev's predicted element eka-aluminium was later discovered as which element?Eka-silicon, predicted by Mendeleev, is the element now called what?Moseley's 1913 X-ray spectra work showed which property to be more fundamental than atomic mass?The Modern Periodic Law relates the properties of elements periodically to their what?Neptunium and plutonium occur naturally in pitchblende, an ore of which metal?What name is given to the horizontal rows of elements in the long form periodic arrangement?How many periods does the modern long form arrangement of elements have?A period number equals which quantity?How many elements does the fourth period contain?Which period contains 32 elements?The fifth period has 18 elements because its filling orbitals total how many?In which order do the 5s, 4d and 5p orbitals increase in energy?Under the 1984 IUPAC recommendation, the element groups are numbered how?Whose work on transuranium elements led to placing the actinoids below the lanthanoids?Element 104 was named Rutherfordium by Americans but by Soviet scientists it was called what?Which IUPAC systematic name belongs to the element with atomic number 101?Element 104 has which IUPAC systematic name?What is the three-letter temporary symbol for element 112?In IUPAC systematic naming, the numerical root used for the digit 0 is what?An undiscovered element with Z = 117 would belong to which group?Element 120 would be expected to belong to which family?Which block of elements is defined by the filling of ns orbitals only, as in groups 1 and 2?Helium is strictly an s-block element, yet it is placed with which group?Hydrogen is placed separately because it can resemble both alkali metals and which family?Compounds of s-block elements are mostly ionic, with the exception of those of which pair?Why are alkali and alkaline earth metals never found free in nature?Group 16 elements are commonly known by which family name?Zn, Cd and Hg lack most transition element properties because their configuration is what?Which series of elements runs from cerium (Z = 58) to lutetium (Z = 71)?The actinoid series extends from thorium to which element?Why are early actinoids chemically more complex than lanthanoids?Silicon, germanium, arsenic and antimony are classed as what type of elements?Which two non-metals are exceptions in having high melting and boiling points?What is the increasing order of metallic character for Si, Be, Mg, Na and P?Within a period, chemical reactivity is highest in group 1 and rises again to a maximum in which group?How does reactivity change on moving down the halogen group?The Cl-Cl bond length in Cl2 is 198 pm. What is the covalent radius of chlorine?Adjacent copper atoms in solid copper are 256 pm apart. What is copper's metallic radius?Roughly how large is the radius of a typical atom?Why does atomic radius generally decrease across a period?The atomic radius of fluorine is 64 pm. What is the radius of the fluoride ion?Sodium has an atomic radius of 186 pm. Which value is the radius of Na+?How many electrons does each of O2-, F-, Na+ and Mg2+ contain?Among the isoelectronic ions O2-, F-, Na+ and Mg2+, which is the smallest?Ionization enthalpy is the energy needed to remove an electron from an atom in which state?On a plot of first ionization enthalpy against atomic number, the maxima occur at which elements?Why is oxygen's first ionization enthalpy below nitrogen's?Na, Mg and Si have first ionization enthalpies 496, 737 and 786 kJ/mol. Al's value is closest to what?Why do halogens have highly negative electron gain enthalpies?Why is fluorine's electron gain enthalpy less negative than chlorine's?Unlike ionization enthalpy, which property is not a directly measurable quantity?Down a transition group, ionization enthalpy shows what trend versus main groups?In group 13, how does electronegativity change from boron to thallium?