In an atom with atomic no. 35 and mass no. 85,the number of electron is:

Options

A. 30
B. 50
C. 35
D. 85

Explanation

To determine the number of electrons in an atom with an atomic number of 35 and a mass number of 85, follow these steps:

### Step-by-Step Solution:

1. **Identify the Atomic Number**: The atomic number of the atom is given as 35. The atomic number (Z) represents the number of protons in the nucleus of the atom.

2. **Understand the Relationship Between Protons and Electrons**: In a neutral atom, the number of protons is equal to the number of electrons. This is because the positive charge of the protons balances the negative charge of the electrons.

3. **Determine the Number of Electrons**: Since the atomic number is 35, this means that there are 35 protons in the atom. Therefore, in a neutral atom, the number of electrons will also be 35.

4. **Conclusion**: The number of electrons in the atom is 35.

### Final Answer:
The number of electrons in the atom is **35**.