Q1 · medium · AI-verified
In Mendeleev's periodic table, the horizontal rows are called periods and vertical columns are called groups. What was the main basis of Mendeleev's classification?
- Increasing atomic mass
- Increasing valency
- Alphabetical order of symbols
- Increasing atomic number
Q2 · easy · AI-verified
How many periods are there in the Modern Periodic Table?
- 7
- 6
- 9
- 8
Q3 · medium · AI-verified
Which of the following properties generally DECREASES on moving from left to right across a period in the modern periodic table?
- Non-metallic character
- Ionization energy
- Electronegativity
- Atomic radius
Q4 · medium · AI-verified
The atomic number of Chlorine is 17. What is the number of valence electrons in a Chlorine atom?
- 7
- 2
- 5
- 1
Q5 · easy · AI-verified
As we move from left to right across a period in the Modern Periodic Table, the atomic size generally:
- Increases
- Decreases
- First increases then decreases
- Remains the same