The atomic number of an element whose atoms have 10 protons and 19 neutrons is .

The atomic number of an element whose atoms have 10 protons and 19 neutrons is 10.

Explanation:

The amount of protons in an element is unique to that specific element and it is also known as the atomic number. If the number of protons were to change to any other number than the element would also change. Protons define the element, and the atomic number is found in the number of protons.

your answer should be 10 :)

Explanation:

metric time was an attempt to create a standard unit of time based off of 10, but it never took off an is not included in the metric system (si)