Answer:
Answered
Step-by-step explanation:
1. He married his second wife before giving divorce to his first wife. This made him an outsider in the scientific community making it difficult for him to raise funds for the research.
2. Back then there were no precise measuring instruments, so it was difficult for him to measure correct data. Many of the elements were yet to be discovered, so he guessed and by fortune most of his guesses were right.
3.The elements that were not discovered at that time, he left blank spaces for them.