Periodic Classification of Elements
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Describe Dobereiner triads, Newlands law of octaves, and Mendeleev periodic table
SubtopicDescribe Dobereiner triads, Newlands law of octaves, and Mendeleev periodic table under Periodic Classification of Elements for Grade 10 CBSE.
Preview questions (no answers)
- 1.
According to Döbereiner, the elements in a triad have similar:
A.Atomic numbers
B.Chemical properties
C.Colors
D.States of matter
- 2.
Which of the following elements did Mendeleev place in Group VIII?
A.Alkali metals
B.Halogens
C.Transition elements like Fe, Co, Ni
D.Noble gases
- 3.
Which element was NOT known when Mendeleev proposed his table?
A.Aluminum
B.Silicon
C.Germanium
D.Copper
- 4.
The Law of Octaves was found to be applicable only to:
A.Heavy elements
B.Lighter elements
C.Transition elements
D.Metalloids
- 5.
What was the basic unit of classification for all three chemists (Döbereiner, Newlands, and Mendeleev)?
A.Atomic volume
B.Atomic mass
C.Atomic number
D.Number of shells
- 6.
Which of the following statements about Mendeleev's Periodic Table is FALSE?
A.It left gaps for undiscovered elements.
B.Elements were arranged in increasing order of atomic mass.
C.Isotopes were given separate positions based on their mass.
D.Groups were determined by the formula of oxides and hydrides.
- 7.
Döbereiner could only identify 3 triads. One was , another was . What was the third?
A.B.C.D. - 8.
Mendeleev's decision to place certain elements out of the order of increasing atomic mass (like and ) was primarily driven by:
A.The need to group elements with similar chemical properties together.
B.A calculation error that he refused to acknowledge.
C.Recent experiments on the radioactivity of these elements.
D.The order of their discovery.
- 9.
In the triad of , the atomic masses of Chlorine and Iodine are 35.5 and 126.9 respectively. What is the approximate atomic mass of Bromine?
A.81.2
B.45.0
C.162.4
D.95.5
- 10.
Which was a major challenge for the classification system of Newlands when compared to Mendeleev?
A.Newlands did not provide any space for new elements, whereas Mendeleev left gaps.
B.Newlands used atomic numbers, which were not yet known.
C.Mendeleev's system only worked for 10 elements.
D.Newlands' system was based on colors.
Download the worksheet for Periodic Classification of Elements - Describe Dobereiner triads, Newlands law of octaves, and Mendeleev periodic table to practice offline. It includes additional chapter-level practice questions.
Explain modern periodic table trends and metallic vs non-metallic properties
SubtopicExplain modern periodic table trends and metallic vs non-metallic properties under Periodic Classification of Elements for Grade 10 CBSE.
Preview questions (no answers)
- 1.
In the modern periodic table, isotopes of an element are placed in:
A.Different groups
B.Different periods
C.The same position
D.Separate blocks at the bottom
- 2.
Which of the following is a non-metal but is lustrous?
A.Carbon
B.Iodine
C.Sulphur
D.Nitrogen
- 3.
Modern Periodic Law was given by:
A.Mendeleev
B.Dobereiner
C.Newlands
D.Henry Moseley
- 4.
As we move across a period, the tendency to lose electrons:
A.Increases
B.Decreases
C.Remains same
D.First increases then decreases
- 5.
The diagram provided shows a segment of the Modern Periodic Table containing four elements and . Based on the horizontal and vertical trends, which of the following statements correctly compares their properties?
A.Element is more metallic than , and element is smaller in size than element .
B.Element is the most electronegative, and element is the most metallic.
C.Element is the most metallic, and element is the smallest in size.
D.Element is more metallic than , and element is larger in size than element .
- 6.
Which of the following elements has the highest ionization energy?
A.B.C.D. - 7.
Moving from left to right in a period, the atomic number increases. This leads to:
A.Decrease in nuclear pull
B.Increase in nuclear pull
C.No change in nuclear pull
D.Decrease in number of protons
- 8.
The relative positions of three elements and in the Modern Periodic Table are shown in the diagram. In the diagram, the arrow from to indicates that and are in the same period with to the left of , and the arrow from to indicates that and are in the same group with located below . If element has the atomic number 16, which of the following statements is correct regarding their properties?
A.Element has a smaller atomic radius than element , and element is more electronegative than element .
B.Elements and belong to the same period, and the metallic character of element is higher than that of element .
C.The valency of element is 2, and element is more non-metallic than element .
D.Element has more valence electrons than element , and element has fewer electron shells than element .
- 9.
An element belongs to Group 13. What is the formula of its sulfate?
A.B.C.D. - 10.
Which of the following statements is true for the Modern Periodic Table?
A.Valency remains the same in a period.
B.Atomic size increases across a period.
C.Metallic character increases down a group.
D.Electronegativity increases down a group.
Download the worksheet for Periodic Classification of Elements - Explain modern periodic table trends and metallic vs non-metallic properties to practice offline. It includes additional chapter-level practice questions.