I'll say francium, if the question is right
Answer:
Comparative- investigations show relationships that do not always indicate cause-and-effect relationships.
Experimental- investigations cannot perfectly reproduce the conditions of the natural world.
Descriptive- investigations often are not repeatable because the results may change over time.
Explanation: I just did this on edge
An ionic bond is formed between metal and non metal when they exchange electrons.
The opposing bond would be covalent which is formed between non metal and non metal.
To form an ionic bond, pair any two metal and non metal that will exchange electrons such as LiBr, NaCl, etc.
Hope this helps!