Question

find the error in the following sentence: "they finally invented the radio active element

Answer 1

radioactive materials are always present and no need to invent it. Hence, the correct usage will be "the finally discovered the radioactive element".

Hope this helps.

Answer 2

Hey mate!

The answer to your question is :
The sentence must begin with capital letter and there must be a full stop at the end and radio active elements are always present and we need not invent them.
They finally invented the redio active element.

Hope it helps you (LOL)....
If yes, then please don't hesitate to mark my answer as brainliest !!!