Final Answer:
1. The given statement The effective nuclear charge (eff) increases as you move across a period (from left to right) in the periodic table is True (option A)
2.The given statement In a given period of the periodic table, the effective nuclear charge (eff) remains constant is False (option B).
3. The given statement The effective nuclear charge (eff) experienced by an electron in an atom is influenced by both the number of protons and the shielding effect of inner electrons is True (option A).
Step-by-step explanation:
1. a) True: The effective nuclear charge (eff) increases as you move across a period (from left to right) in the periodic table. This is due to the increase in the number of protons in the nucleus, which attracts the electrons more strongly, leading to a higher effective nuclear charge experienced by the outer electrons.
2. b) False: In a given period of the periodic table, the effective nuclear charge (eff) does not remain constant. As you move across a period, the number of protons in the nucleus increases, resulting in a higher effective nuclear charge. This increasing effective nuclear charge is a significant factor in the periodic trends of the elements.
3. a) True: The effective nuclear charge (eff) experienced by an electron in an atom is indeed influenced by both the number of protons in the nucleus and the shielding effect of inner electrons. The shielding effect refers to the repulsion between electrons in different energy levels, which reduces the net positive charge felt by the outer electrons, affecting the overall effective nuclear charge.
In summary, the effective nuclear charge is a dynamic factor influenced by the number of protons and the shielding effect of inner electrons. These considerations play a crucial role in understanding the behavior and properties of elements across periods in the periodic table.