Question

1. __ in solids are very close together. 9. a liquid has definite __. and a definite

Explanation:

Question 7

In the context of the structure of solids, the particles (atoms, molecules, or ions) are closely packed, which is a key concept in the study of matter in physics (a subfield of Natural Science) related to the states of matter. So the word that fits here is "Particles" as particles in solids have strong intermolecular forces holding them close together.

Question 9

In the study of the states of matter (a topic in Physics, part of Natural Science), a liquid is known to have a definite volume. This is because the particles in a liquid are close enough that they maintain a relatively fixed amount of space they occupy (volume), but they can flow and take the shape of their container (so they don't have a definite shape). So the word that fits in the blank for "A liquid has definite ______" is "volume".

Answer:

Particles