To calculate the number of electrons in Chromium (Cr) with atomic number (Z) = 24, where the angular momentum quantum number (l) = 0 and the magnetic quantum number (m) = 0, we need to analyze the electronic configuration of Chromium.

Understanding Electron Configuration
- Chromium has an atomic number of 24, which means it has 24 electrons in its neutral state.
- The electron configuration of Chromium is typically written as:
1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹.

Quantum Numbers Overview
- Quantum numbers define the properties of atomic orbitals and the electrons in them.
- The angular momentum quantum number (l) = 0 indicates the electron is in an 's' orbital.
- The magnetic quantum number (m) = 0 specifies that the electron has no angular momentum projection, which is also characteristic of 's' orbitals.

Electrons with l = 0, m = 0
- Since l = 0 corresponds to the 's' orbital, we focus on the electrons in the 's' orbitals within the configuration of Chromium.
- From the configuration, we see that there are:
- 2 electrons in the 1s orbital (l=0)
- 2 electrons in the 2s orbital (l=0)
- 2 electrons in the 3s orbital (l=0)

Total Count of Electrons with l = 0, m = 0
- Adding the contributions from the 's' orbitals:
2 (1s) + 2 (2s) + 2 (3s) = 6 electrons.

Conclusion
- Therefore, the total number of electrons in Chromium (Cr) with l = 0 and m = 0 is **6 electrons**.