The atomic number of helium is 2 and the atomic number of lithium is 3. Is it possible to have an element with atomic number 2.5?

Explanation

To determine whether it is possible to have an element with an atomic number of 2.5, we need to understand what atomic number represents.

### Step-by-Step Solution:

1. **Definition of Atomic Number**: The atomic number of an element is defined as the number of protons in the nucleus of an atom. In a neutral atom, the number of protons is equal to the number of electrons.

2. **Understanding Atomic Numbers**: For helium (He), the atomic number is 2, meaning it has 2 protons and 2 electrons. For lithium (Li), the atomic number is 3, indicating it has 3 protons and 3 electrons.

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