Periodic Classification of Elements
- Compare and contrast the arrangement of elements in Mendeleev's Periodic Table and the Modern Periodic Table. Mendeleev's periodic table Modern periodic table Elements are arranged in the increasing order of their atomic masses. Elements are arranged... 1
- In the Modern Periodic Table, calcium (atomic number 20) is surrounded by elements with atomic numbers The element with atomic number 12 has same chemical properties as that of calcium. This is because both of them have same number of valence... 2
- How does the electronic configuration of an atom relate to its position in the Modern Periodic Table? In the modern periodic table, atoms with similar electronic configurations are placed in the same column. In a group, the number of valence... 1
- Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the Periodic Table. Nitrogen (7): 2, 5 Phosphorus (15): 2, 8, 5 Since, electronegativity decreases with moving from top to bottom in a group, thus Nitrogen will... 1
- The position of three elements A, B and C in the Periodic Table are shown below - Group 16 Group 17 (a) A is a non-metal. (b) C is less reactive than A, as reactivity decreases down the group in halogens. (c) C will be smaller in size than... 1
- An atom has electronic configuration 2, 8, 7. (a) What is the atomic number of this element? (a) The atomic number of this element is 17. (b) It would be chemically similar to F(9) with configuration as 2, 7. 1
- What property do all elements in the same column of the Periodic Table as fluorine have in common Valency equal to 1. 2
- What property do all elements in the same column of the Periodic Table as boron have in common? Valency equal to 3. 2
- Which element has (a) two shells, both of which are completely filled with electrons? (a) Neon (b) Magnesium (c) Silicon (d) Boron (e) Carbon 2
- Element X forms a chloride with the formula XCl2, which is a solid with a high melting point. Correct option is (b) Mg 2
- Which of the following statements is not a correct statement about the trends when going from left Correct option is (c) The atoms lose their electrons more easily. 1
- By considering their position in the Periodic Table, which one of the following elements Since Be lies to the extreme left hand side of the periodic table, Be is the most metallic among the given elements. 1
- In the Modern Periodic Table, which are the metals among the first ten elements? Among the first ten elements, lithium (Li) and beryllium (Be) are metals. 1
- Helium is an unreactive gas and neon is a gas of extremely low reactivity. What, if anything, Both helium (He) and neon (Ne) have filled outermost shells. Helium has a duplet in its K shell, while neon has an octet in its L shell. 1
- Lithium, sodium, potassium are all metals that react with water to liberate hydrogen gas. Is there any Yes. The atoms of all the three elements lithium, sodium, and potassium have one electron in their outermost shells. 1
- Name (c) three elements with filled outermost shells. Neon (Ne), argon (Ar), and xenon (Xe) have filled outermost shells. 1
- Name (b) two elements that have two electrons in their outermost shells. Magnesium (Mg) and calcium (Ca) have two electrons in their outermost shells. 1
- Name (a) three elements that have a single electron in their outermost shells. Lithium (Li), sodium (Na), and potassium (K) have a single electron in their outermost shells. 1
- Name two elements you would expect to show chemical reactions similar to magnesium. Calcium (Ca) and strontium (Sr) are expected to show chemical reactions similar to magnesium (Mg). This is because the number of valence ele... 1
- How could the Modern Periodic Table remove various anomalies of Mendeleev's Periodic Table? Various anomalies of Mendeleev’s Periodic Table removed as follows in the Modern Periodic Table: → Elements are arranged in the increasing o... 2
- Why do you think the noble gases are placed in a separate group? Noble gases are inert elements. Their properties are different from the all other elements. Therefore, the noble gases are placed in a separ... 1
- What were the criteria used by Mendeleev in creating his Periodic Table? Mendeleev used atomic mass of the elements as the unique criteria of the elements. He proposed that the chemical properties of elements are... 2
- Besides gallium, which other elements have since been discovered that were left by Mendeleev in his Periodic Table? Scandium and germanium. 2
- Use Mendeleev's Periodic Table to predict the formulae for the oxides of the following elements: K, C, Al, Si, Ba. K is in group 1. Therefore, the oxide will be K₂O. C is in group 4. Therefore, the oxide will be CO₂. Al is in group 3. Therefore, the oxide... 1