How many protons and neutrons are present in the following nuclei?
`""_(2)^(4)He, ""_(6)^(12)C, ""_(18)^(40)Ar, ""_(10)^(22)Ne, ""_(92)^(235)U`

Answer

To determine the number of protons and neutrons in the given nuclei, we will use the following definitions:

1. **Atomic Number (Z)**: This is the number of protons in the nucleus of an atom.
2. **Atomic Mass (A)**: This is the total number of protons and neutrons in the nucleus of an atom.

The number of neutrons can be calculated using the formula:
\[ \text{Number of Neutrons} = \text{Atomic Mass} - \text{Atomic Number} \]

Now, let's apply this to each of the given nuclei:

### 1. Helium (He)
- Given: \( _{2}^{4}\text{He} \)
- Atomic Number (Z) = 2 (number of protons)
- Atomic Mass (A) = 4

**Calculating Neutrons:**
\[ \text{Number of Neutrons} = A - Z = 4 - 2 = 2 \]

**Result for Helium:**
- Protons = 2
- Neutrons = 2

### 2. Carbon (C)
- Given: \( _{6}^{12}\text{C} \)
- Atomic Number (Z) = 6 (number of protons)
- Atomic Mass (A) = 12

**Calculating Neutrons:**
\[ \text{Number of Neutrons} = A - Z = 12 - 6 = 6 \]

**Result for Carbon:**
- Protons = 6
- Neutrons = 6

### 3. Argon (Ar)
- Given: \( _{18}^{40}\text{Ar} \)
- Atomic Number (Z) = 18 (number of protons)
- Atomic Mass (A) = 40

**Calculating Neutrons:**
\[ \text{Number of Neutrons} = A - Z = 40 - 18 = 22 \]

**Result for Argon:**
- Protons = 18
- Neutrons = 22

### 4. Neon (Ne)
- Given: \( _{10}^{22}\text{Ne} \)
- Atomic Number (Z) = 10 (number of protons)
- Atomic Mass (A) = 22

**Calculating Neutrons:**
\[ \text{Number of Neutrons} = A - Z = 22 - 10 = 12 \]

**Result for Neon:**
- Protons = 10
- Neutrons = 12

### 5. Uranium (U)
- Given: \( _{92}^{235}\text{U} \)
- Atomic Number (Z) = 92 (number of protons)
- Atomic Mass (A) = 235

**Calculating Neutrons:**
\[ \text{Number of Neutrons} = A - Z = 235 - 92 = 143 \]

**Result for Uranium:**
- Protons = 92
- Neutrons = 143

### Summary of Results:
- Helium: Protons = 2, Neutrons = 2
- Carbon: Protons = 6, Neutrons = 6
- Argon: Protons = 18, Neutrons = 22
- Neon: Protons = 10, Neutrons = 12
- Uranium: Protons = 92, Neutrons = 143