Among the following pairs of orbital which orbital will experience the larger effective nuclear charge?
a. `2s and 3s`, b. `4d and 4f`, c. `3d and 3p`

Explanation

To determine which orbital experiences a larger effective nuclear charge among the given pairs, we need to consider the concept of effective nuclear charge (Z_eff). The effective nuclear charge is the net positive charge experienced by an electron in a multi-electron atom, which is influenced by the distance of the orbital from the nucleus and the shielding effect of other electrons.

### Step-by-Step Solution:

1. **Understanding Effective Nuclear Charge**:
- The effective nuclear charge is influenced by two main factors: the actual nuclear charge (Z) and the shielding effect caused by other electrons. The closer an orbital is to the nucleus, the greater the effective nuclear charge it experiences.

2. **Analyzing the First Pair: 2s and 3s**:
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