The atomic number of an element is 34 and the mass number is 79. The number of electrons in the outer most shell is:

Answer

To find the number of electrons in the outermost shell of an element with atomic number 34 and mass number 79, we can follow these steps:

### Step 1: Identify the Element
The atomic number of the element is 34. This corresponds to the element Selenium (Se) in the periodic table.

### Step 2: Determine the Electronic Configuration
To find the electronic configuration, we need to fill the electrons according to the Aufbau principle. The order of filling is as follows:
1. 1s
2. 2s
3. 2p
4. 3s
5. 3p
6. 4s
7. 3d
8. 4p

Now, we fill the electrons up to atomic number 34:
- 1s² (2 electrons)
- 2s² (2 electrons)
- 2p⁶ (6 electrons)
- 3s² (2 electrons)
- 3p⁶ (6 electrons)
- 4s² (2 electrons)
- 3d¹⁰ (10 electrons)
- 4p⁴ (4 electrons)

Adding these gives us:
- 2 + 2 + 6 + 2 + 6 + 2 + 10 + 4 = 34 electrons

### Step 3: Identify the Outermost Shell
The outermost shell for Selenium (Se) is the fourth shell (n=4), which includes the 4s and 4p subshells.

### Step 4: Count the Electrons in the Outermost Shell
In the outermost shell (4th shell), we have:
- 4s² (2 electrons)
- 4p⁴ (4 electrons)

Adding these gives us:
- 2 (from 4s) + 4 (from 4p) = 6 electrons

### Conclusion
The number of electrons in the outermost shell of the element with atomic number 34 is **6**.

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