An element of atomic number 29 belongs to
Block classification by atomic number
Atomic number 29 is Cu: [Ar] 3d¹⁰ 4s¹ → d-block
Element X has six more protons than element Y. Which statement must be correct?
Relationship between elements differing by 6 protons
Period 3 has 8 elements e.g. Na(11) and Cl(17) differ by 6 and are in same period
Which of the following is incorrect for an element having atomic number 19?
Properties of element with Z=19
Z=19 is Potassium (K), which is an alkali metal (group 1), not alkaline earth
Variable valency is generally exhibited by
Variable valency characteristic
Transition metals have partially filled d-orbitals enabling variable oxidation states
Choose the more appropriate statement for the d-block elements.
Properties of d-block (transition) elements
The defining characteristic of d-block is where the last electron is placed
Which periods in the periodic table have 18 elements?
Number of elements in periods
Periods 4 and 5 include s, d, and p-block elements totalling 18 each
An element Y is present in the 3rd period and has a valence shell configuration of ns²np⁴. Most probably element Y is
Identifying element from period and configuration
ns²np⁴ = group 16; Period 3 group 16 element is Sulfur (S)
An element has an atomic number of 27. To which block does this belong?
Block identification from atomic number
Atomic number 27 is Co: [Ar] 3d⁷ 4s² → d-block
Isotopes have
Isotopes are atoms of the same element with different mass numbers
Which is the most appropriate statement regarding the modern periodic table?
Moseley revised Mendeleev's periodic law using atomic number
The properties of an element in the periodic table depend on its
Basis of periodic properties
Periodic properties are determined by electron arrangement
An element with a general valence shell electronic configuration of ns¹(n-1)d⁵ most probably will be
Identifying element from special electronic configuration
4s¹ 3d⁵ is the anomalous half-filled configuration of Chromium (Cr)
Which of the following is not a representative element?
Identifying non-representative elements
Fe is a transition metal (d-block), not a representative element
Halogens are present in which group of the periodic table?
Group position of halogens
Halogens (F, Cl, Br, I) are in Group 17
An element X is present in group 1 and lies in period 4. Most probably, the element X is
Identifying element by group and period
Group 1, Period 4 = Potassium (K), atomic number 19
Representative elements belong to
Classification of representative elements
Representative (main group) elements are in s and p blocks
Which of the following pairs of elements belong to the same period?
Identifying elements in the same period
Na (Z=11) and Cl (Z=17) are both in Period 3
An element with a valence shell electronic configuration ns² belongs to
Block classification from electronic configuration
ns² has 2 valence electrons → Group 2 (alkaline earth metals)
