1.

Scientists DO NOT base their knowledge about a subject on .

ideas

evidence

observations

2.

Scientists collect evidence by making of the world around them.

opinions

observations

good guesses

3.

In the wild, we can observe animals and collect about their behaviors.

data

hypotheses

opinions

Ideas, observations, and dat

Explanation:

the answer is na (sodium)

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.