Explanation:
The nucleus of an atom is dense because it contains more of particles in a very little space.
The nucleus is the center of an atom made up of the protons and neutrons.
Atomic nucleus is very small compared to the size of the atom.
Density is function of mass and volume.
Mass is the amount of matter in a substance.
Volume is the space occupied by a substance.
The more the mass the more the density.
Since protons and neutron are massive bodies occupying a small space, they make the nucleus very dense.
learn more:
Density brainly.com/question/5055270
#learnwithBrainly
Answer:
1. The best definition of refraction is ____.
a. passing through a boundary
b. bouncing off a boundary
c. changing speed at a boundary
d. changing direction when crossing a boundary
Answer: D
Bouncing off a boundary (choice b) is reflection. Refraction involves passing through a boundary (choice a) and changing speed (choice c); however, a light ray can exhibit both of these behaviors without undergoing refraction (for instance, if it approaches the boundary along the normal). Refraction of light must involve a change in direction; the path must be altered at the boundary.