Solve the programming task below in a Python markdown code block.
An array is called `zero-balanced` if its elements sum to `0` and for each positive element `n`, there exists another element that is the negative of `n`. Write a function named `ìsZeroBalanced` that returns `true` if its argument is `zero-balanced` array, else return `false`. Note that an `empty array` will not sum to `zero`.
Also feel free to reuse/extend the following starter code:
```python
def is_zero_balanced(arr):
```