Periodic Classification of Elements (Class 10 Science)
The periodic table organizes elements based on their atomic number and chemical properties. Understanding periodic trends helps predict element behavior an
TL;DR: The periodic table organizes elements based on their atomic number and chemical properties. Understanding periodic trends helps predict element behavi…
Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated
The periodic table organizes elements based on their atomic number and chemical properties. Understanding periodic trends helps predict element behavior an
Periodic Classification of Elements MCQs with Answers & Explanations
Q1. Who arranged the periodic table by atomic number?
- John Newlands
- Julius Lothar Meyer
- Henry Moseley ✓ (correct)
- Dmitri Mendeleev
Explanation: Henry Moseley discovered that atomic number (number of protons) is more fundamental than atomic mass for organizing elements.
Q2. Elements in the same group of the periodic table have:
- Same atomic number
- Same number of shells
- Same atomic mass
- Same number of valence electrons ✓ (correct)
Explanation: Elements in the same group (vertical column) have the same number of valence electrons, which determines their chemical properties.
Q3. Which of the following is a property of metals?
- Good conductors of heat and electricity ✓ (correct)
- Poor conductors of electricity
- Non-lustrous
- Brittle
Explanation: Metals are good conductors of heat and electricity, are malleable, ductile, and lustrous (shiny).
Q4. The element with atomic number 6 is:
- Nitrogen
- Carbon ✓ (correct)
- Boron
- Oxygen
Explanation: Carbon has 6 protons and is the foundation of all organic molecules.
Q5. Across a period in the periodic table, atomic radius:
- Increases then decreases
- Remains constant
- Decreases ✓ (correct)
- Increases
Explanation: Atomic radius decreases across a period because the nuclear charge increases while electrons are added to the same shell.
Q6. Which of the following is a halogen?
- Oxygen
- Nitrogen
- Helium
- Fluorine ✓ (correct)
Explanation: Halogens are Group 17 elements; fluorine (F) is the most reactive halogen.
Q7. Noble gases have a valence shell that is:
- Completely full ✓ (correct)
- Empty
- Has one electron
- Half full
Explanation: Noble gases have a complete valence shell (8 electrons except He with 2), making them extremely stable and unreactive.
Q8. Electronegativity increases across a period and:
- Remains constant down a group
- Decreases down a group ✓ (correct)
- Increases down a group
- Increases then decreases down a group
Explanation: Electronegativity decreases down a group because the valence electrons are farther from the nucleus.
Q9. Which element is a non-metal located in Group 15?
- Sulfur
- Argon
- Phosphorus ✓ (correct)
- Chlorine
Explanation: Phosphorus (P) is a non-metal in Group 15 with 5 valence electrons.
Q10. The first ionization energy is the energy required to:
- Add an electron to an atom
- Break a bond between atoms
- Melt a solid
- Remove one electron from an atom ✓ (correct)
Explanation: First ionization energy is the energy needed to remove the most loosely bound electron from an isolated atom.
Frequently Asked Questions
What are the differences between metals, non-metals, and metalloids?
Metals are good conductors with luster and malleability. Non-metals are poor conductors and form covalent bonds. Metalloids have properties intermediate between metals and non-metals.
How did Mendeleev predict the properties of undiscovered elements?
Mendeleev arranged elements by atomic mass and left gaps for unknown elements, predicting their properties based on neighboring elements' characteristics. When gallium, scandium, and germanium were discovered, their properties closely matched his predictions.
More Class 10 Science MCQs
- Light Reflection and Refraction
- Electricity
- Acids Bases and Salts
- Life Processes
- Carbon and its Compounds
- Metals and Non-metals
🤖 Stuck on any of these? Ask Syllab's free AI Tutor to explain step by step →