Answer:
Modern periodic law states that the properties of elements are dependent on their atomic numbers and elements show similar properties at regular interval of increasing atomic number.
Question 2 :
- Fluorine
- Chlorine
- Bromine
- Iodine
- Astatine
Question 3 :
3. Ionic Bond .
Reason : The elements from Group I are metals ( they lose electrons )
The elements from Group 17 are non-metals ( they Gain electrons