Online Test — The Periodic Table
25 Questions • 15 min • Chapter MCQ
15:00
Question 1 of 25
A Dobereiner's triad is a group of how many elements?
Two
Three
Eight
Ten
Explanation: A triad is a group of three elements with similar properties.
Question 2 of 25
In a triad, the atomic mass of the middle element is about the ______ of the other two.
Sum
Average
Difference
Product
Explanation: The middle element's atomic mass is roughly the average of the other two.
Question 3 of 25
Newlands arranged elements in order of increasing:
Atomic number
Atomic mass
Size
Colour
Explanation: Newlands arranged elements by increasing atomic mass.
Question 4 of 25
In Newlands' Law of Octaves, similar properties repeated after every ______ element.
Second
Fourth
Eighth
Tenth
Explanation: Every eighth element had similar properties (like musical octaves).
Question 5 of 25
A limitation of Newlands' octaves was that it worked only for:
Heavier elements
Lighter elements
Gases only
Metals only
Explanation: The Law of Octaves worked only for the lighter elements.
Question 6 of 25
Mendeleev arranged the elements in order of increasing:
Atomic number
Atomic mass
Density
Size
Explanation: Mendeleev arranged elements by increasing atomic mass.
Question 7 of 25
Mendeleev placed elements with similar properties in the same:
Row
Vertical column (group)
Corner
Diagonal
Explanation: Similar elements were placed in the same vertical column (group).
Question 8 of 25
For undiscovered elements, Mendeleev:
Ignored them
Left gaps and predicted their properties
Removed similar elements
Stopped the table
Explanation: He left gaps and predicted the properties of undiscovered elements.
Question 9 of 25
Mendeleev is often called the:
Father of physics
Father of the periodic table
Inventor of atoms
Discoverer of electrons
Explanation: Mendeleev is called the father of the periodic table.
Question 10 of 25
A limitation of Mendeleev's table was the uncertain position of:
Oxygen
Hydrogen
Iron
Gold
Explanation: The position of hydrogen was uncertain in Mendeleev's table.
Question 11 of 25
The Modern Periodic Law states that properties are a periodic function of the element's:
Atomic mass
Atomic number
Density
Size
Explanation: The modern law uses atomic number as the basis for periodicity.
Question 12 of 25
The modern periodic table arranges elements in order of increasing:
Atomic mass
Atomic number
Valency
Colour
Explanation: Elements are arranged by increasing atomic number.
Question 13 of 25
The horizontal rows of the periodic table are called:
Groups
Periods
Blocks
Triads
Explanation: Horizontal rows are called periods (there are 7).
Question 14 of 25
The number of groups (vertical columns) in the modern periodic table is:
7
8
18
118
Explanation: There are 18 groups in the modern periodic table.
Question 15 of 25
Elements in the same group have similar properties because they have the same number of:
Neutrons
Valence electrons
Protons
Shells
Explanation: Same-group elements have the same number of valence electrons.
Question 16 of 25
Across a period (left to right), the atomic radius generally:
Increases
Decreases
Stays the same
Doubles
Explanation: Atomic radius decreases across a period as nuclear charge increases.
Question 17 of 25
Down a group, the atomic radius generally:
Decreases
Increases
Stays the same
Becomes zero
Explanation: Atomic radius increases down a group due to extra electron shells.
Question 18 of 25
Ionisation energy generally ______ across a period.
Decreases
Increases
Stays the same
Becomes negative
Explanation: Ionisation energy increases across a period (electrons held more tightly).
Question 19 of 25
Metallic character generally ______ across a period.
Increases
Decreases
Stays the same
Doubles
Explanation: Metallic character decreases across a period (more non-metallic to the right).
Question 20 of 25
Electronegativity generally ______ down a group.
Increases
Decreases
Stays the same
Becomes zero
Explanation: Electronegativity decreases down a group.
Question 21 of 25
Which of these is a typical property of metals?
Dull and brittle
Shiny and good conductor
Poor conductor
Always a gas
Explanation: Metals are shiny (lustrous) and good conductors of heat and electricity.
Question 22 of 25
The ability of a metal to be drawn into wires is called:
Malleability
Ductility
Brittleness
Sonority
Explanation: Ductility is the ability to be drawn into wires.
Question 23 of 25
Which of these is a non-metal?
Iron
Copper
Oxygen
Gold
Explanation: Oxygen is a non-metal; the others are metals.
Question 24 of 25
Elements with properties between metals and non-metals are called:
Alloys
Metalloids
Isotopes
Salts
Explanation: Metalloids have properties in between metals and non-metals.
Question 25 of 25
Silicon, a metalloid, is widely used in:
Cooking
Computer chips (electronics)
Lighting fires
Making paper
Explanation: Silicon is a semiconductor used in computer chips and electronics.