How can elements properties be predicted?

Hint: In modern periodic tables, elements have been arranged according to their atomic numbers which is directly related to their physical and chemical properties. All the elements show periodicity in their physical and chemical properties in the periodic table.

Complete step by step answer:
- The modern periodic law states that the properties of the elements are periodic functions of their atomic number. In other words, properties of an element can be determined by their position on the periodic table.
- This law helps to give better understanding about the physical and chemical properties of elements.
- In the modern periodic table, elements have been arranged according to their increasing atomic numbers.
- There are 18 groups and 7 periods in a periodic table. Elements of the same group have similar outer electronic configuration.
- The periodic number corresponds to the highest principal quantum number (n) of the elements in the period.
- Elements have certain properties which show very clear periodic trends. Few of these properties are atomic radius, ionization energy, electronegativity, etc.
- As we move from left to right in a period, atomic number of elements increases so nuclear charge increases while number of shells in elements remain the same. Thus, atomic radius gradually decreases.
- Since the atomic size decreases and the nuclear charge increases, the ionization energy gradually increases.
- As we already know, with increase in nuclear charge, the electron loving character also increases. As a result, the electronegativity also increases.

Note: Every chemical element has a unique atomic number that represents the number of protons in its nucleus. Most elements have contrasting quantities of neutrons among various atoms, with these variations referred to as isotopes.