Answer:
In general, print publications with authors and listed sources tend to be reliable because they provide sources which readers can verify. Likewise, Web postings with a .gov (posted by the United States government) are both current and reliable.
Explanation:
The the exact mass is 24.740% (according to the internet) but I’d say that it’s 25
Multiple states of matter - mixture
Same state of matter - pure
Separated physically- mixture
Consistent properties - pure
Can’t be separated- pure
Can’t be a single element - mixture