Vidaara.orgClass 8 · Mathematics
CodeVID-M8-WS
The Periodic Table — Practice Worksheet
Name: ____________________
Roll No.: __________
Date: ____________
General Instructions
- All questions are compulsory.
- Choose the correct option (A, B, C or D) for each question.
- The answer key is at the end — try the paper first!
Section A — Multiple Choice (1 mark each)
25 × 1 = 25 marks
1.
A Dobereiner's triad is a group of how many elements?
- A.Two
- B.Three
- C.Eight
- D.Ten
2.
In a triad, the atomic mass of the middle element is about the ______ of the other two.
- A.Sum
- B.Average
- C.Difference
- D.Product
3.
Newlands arranged elements in order of increasing:
- A.Atomic number
- B.Atomic mass
- C.Size
- D.Colour
4.
In Newlands' Law of Octaves, similar properties repeated after every ______ element.
- A.Second
- B.Fourth
- C.Eighth
- D.Tenth
5.
A limitation of Newlands' octaves was that it worked only for:
- A.Heavier elements
- B.Lighter elements
- C.Gases only
- D.Metals only
6.
Mendeleev arranged the elements in order of increasing:
- A.Atomic number
- B.Atomic mass
- C.Density
- D.Size
7.
Mendeleev placed elements with similar properties in the same:
- A.Row
- B.Vertical column (group)
- C.Corner
- D.Diagonal
8.
For undiscovered elements, Mendeleev:
- A.Ignored them
- B.Left gaps and predicted their properties
- C.Removed similar elements
- D.Stopped the table
9.
Mendeleev is often called the:
- A.Father of physics
- B.Father of the periodic table
- C.Inventor of atoms
- D.Discoverer of electrons
10.
A limitation of Mendeleev's table was the uncertain position of:
- A.Oxygen
- B.Hydrogen
- C.Iron
- D.Gold
11.
The Modern Periodic Law states that properties are a periodic function of the element's:
- A.Atomic mass
- B.Atomic number
- C.Density
- D.Size
12.
The modern periodic table arranges elements in order of increasing:
- A.Atomic mass
- B.Atomic number
- C.Valency
- D.Colour
13.
The horizontal rows of the periodic table are called:
- A.Groups
- B.Periods
- C.Blocks
- D.Triads
14.
The number of groups (vertical columns) in the modern periodic table is:
- A.7
- B.8
- C.18
- D.118
15.
Elements in the same group have similar properties because they have the same number of:
- A.Neutrons
- B.Valence electrons
- C.Protons
- D.Shells
16.
Across a period (left to right), the atomic radius generally:
- A.Increases
- B.Decreases
- C.Stays the same
- D.Doubles
17.
Down a group, the atomic radius generally:
- A.Decreases
- B.Increases
- C.Stays the same
- D.Becomes zero
18.
Ionisation energy generally ______ across a period.
- A.Decreases
- B.Increases
- C.Stays the same
- D.Becomes negative
19.
Metallic character generally ______ across a period.
- A.Increases
- B.Decreases
- C.Stays the same
- D.Doubles
20.
Electronegativity generally ______ down a group.
- A.Increases
- B.Decreases
- C.Stays the same
- D.Becomes zero
21.
Which of these is a typical property of metals?
- A.Dull and brittle
- B.Shiny and good conductor
- C.Poor conductor
- D.Always a gas
22.
The ability of a metal to be drawn into wires is called:
- A.Malleability
- B.Ductility
- C.Brittleness
- D.Sonority
23.
Which of these is a non-metal?
- A.Iron
- B.Copper
- C.Oxygen
- D.Gold
24.
Elements with properties between metals and non-metals are called:
- A.Alloys
- B.Metalloids
- C.Isotopes
- D.Salts
25.
Silicon, a metalloid, is widely used in:
- A.Cooking
- B.Computer chips (electronics)
- C.Lighting fires
- D.Making paper
Answer Key
Section A — Multiple Choice (1 mark each)
- (B) Three
- (B) Average
- (B) Atomic mass
- (C) Eighth
- (B) Lighter elements
- (B) Atomic mass
- (B) Vertical column (group)
- (B) Left gaps and predicted their properties
- (B) Father of the periodic table
- (B) Hydrogen
- (B) Atomic number
- (B) Atomic number
- (B) Periods
- (C) 18
- (B) Valence electrons
- (B) Decreases
- (B) Increases
- (B) Increases
- (B) Decreases
- (B) Decreases
- (B) Shiny and good conductor
- (B) Ductility
- (C) Oxygen
- (B) Metalloids
- (B) Computer chips (electronics)
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