Matter

3. The phase change from liquid to solid
4. The smallest unit of matter
7. Anything that has mass and occupies space
10. Proton + Neutron
13. A positively charged atom
14. The way that a substance reflects light (metallic, non-metallic, glassy, pearly, dull).
15. The highest density element
17. a particle with a negative charge
18. The phase change from solid directly to gas without passing through the liquid state
19. The lowest density element
20. how the object absorbs and reflects light

1. A charged atom
2. An atom that has neither a positive nor a negative charge
5. Ability of a substance to be hammered flat and to retain the new shape.
6. An element with 6 protons
8. The amount of matter in an object (in g or kg).
9. Same number of protons, different number of neutrons
11. The phase change from solid to liquid, typically due to an increase in temperature that breaks the intermolecular bonds holding the solid together.
12. The phase change from gas directly to solid, where gas molecules lose energy and come together to form a solid structure without passing through the liquid phase.
16. A measure of the average kinetic energy (energy of motion) of particles in a substance.