What are primary and secondary valencies according to modern concept?

Explanation

**Step-by-Step Solution:**

1. **Understanding Primary and Secondary Valencies**:
- According to the modern concept, the primary valency refers to the oxidation number of the central metal atom in a coordination compound.
- The secondary valency refers to the coordination number, which is the total number of ligand atoms that are directly bonded to the central metal atom.

2. **Identifying the Coordination Compound**:
- Let's consider the example coordination compound \( K_2[PtF_6] \).
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