Given below are two statements:
Statement (I): The 4 and 5- series of elements are placed separately in the Periodic table to preserve the principle of classification.
Statement (II): s-block elements can be found in pure form in nature.
In the light of the above statements, choose the most appropriate answer from the options given below: [2024]
Both Statement I and Statement II are false
Statement I is false but Statement II is true
Statement I is true but Statement II is false
Both Statement I and Statement II are true
(3)
Statement I: Outermost shell for 4f series elements is 6th shell, hence these are placed in 6th period. Outermost shell for 5f series elements is 7th shell, hence these are placed in 7th period. This is a true statement.
Statement II: s-block elements are highly reactive and are not found in pure form in nature.
If IUPAC name of an element is ''Unununnium" then the element belongs to nth group of Periodic table. The value of n is _________ . [2024]
(11)
Unununnium is 111 (un mean 1, nium is added as a convension).
Element with atomic number 118 is last element of periodic table i.e., belongs to group 18. Starting backwards, 117 → group 17, 116 → group 16, 115 → group 15, 114 → group 14, 113 → group 13, 112 → group 12, 111 → group 11.
Given below are two statements about X-ray spectra of elements : [2025]
Statement I: A plot of ( = frequency of X-rays emitted) vs atomic mass is a straight line.
Statement II: A plot of ( = frequency of X-rays emitted) vs atomic number is a straight line.
In the light of the above statements, choose the correct answer from the options given below :
Statement I is true but Statement II is false
Both Statement I and Statement II are false
Both Statement I and Statement II are true
Statement I is false but Statement II is true
(4)
Henry Moseley observed regularities in the characteristic X-ray spectra of the elements. A plot of (where is frequency of X-rays emitted) against atomic number (Z) gave a straight line and not the plot of vs atomic mass. He thereby showed that the atomic number is a more fundamental property of an element than its atomic mass.
Which of the following statements are NOT true about the periodic table? [2025]
(A) The properties of elements are function of atomic weights.
(B) The properties of elements are function of atomic numbers.
(C) Elements having similar outer electronic configurations are arranged in same period.
(D) An element’s location reflects the quantum numbers of the last filled orbital.
(E) The number of elements in a period is same as the number of atomic orbitals available in energy level that is being filled.
Choose the correct answer from the options given below:
(B), (C) and (E) Only
(A) and (E) Only
(D) and (E) Only
(A), (C) and (E) Only
(4)
(A)(B) Properties of elements are periodic function of atomic number, not atomic mass.
(C) Elements with similar outer electronic configuration are arranged in same group.
(D) An element present in 4th period, p block will have last electron filled in 4p orbital, so an element’s location in periodic table reflects the quantum numbers of last filled orbital.
(E) In third period there are 8 elements but third shell has 9 orbitals.
Given below are two statements: [2025]
Statement I: According to the law of Octaves, the elements were arranged in the increasing order of their atomic number.
Statement II: Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic numbers.
In the light of the above Statements, choose the correct answer from the options given below:
Both Statement I and Statement II are true.
Statement I is false but Statement II is true.
Statement I is true but Statement II is false.
Both Statement I and Statement II are false.
(4)
Statement I: Law of Octaves (given by John Alexander Newlands in 1865) – When elements are arranged in increasing order of their atomic mass then every eighth element has properties similar to the first element.
Statement II: Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic mass.
