The dens or the odontoid process of the axis or the second cervical spine forms a pivot point with the atlas or the first cervical vertebrae that is responsible for the nodding and the rotational movements of the head. This is reinforced by ligaments and the atlanto-occipital joint that allows the head to make a nodding or up and down movement on the vertebral column.
Answer:All three states of matter (solid, liquid and gas) expand when heated. ... Heat causes the molecules to move faster, (heat energy is converted to kinetic energy ) which means that the volume of a gas increases more than the volume of a solid or liquid.
Explanation:well I tried lol she just copied and pasted faster than I could
Answer:
1. Reflection
2. travel from one medium to another
3. Same waves to travel in opposite direction.
Explanation:
1. When a wave strikes a solid barrier, it bounces back in the same medium. This wave behavior of bouncing back is known as reflection. Its like a basketball hitting a backboard. The ball bounces back at the same angle as it was incident. ∠i = ∠r
2. For refraction to occur in a wave, the wave must travel from one medium to another. When light travels from through mediums of different optical densities, it bends. The wave bends away normal when it enters from denser medium to rarer medium. The wave bends towards the normal when it enters from rarer to denser medium. The angle of refraction and angle of incidence are related by Snell's law.

3. The formation of standing wave requires two same waves to travel in the opposite direction and interfere. The incident wave and reflected wave when interfere, form standing waves. There waves are also resonances or harmonics. A standing wave oscillates at one place and does not transfers any energy.
Answer:
Atomic number is the number of protons in the nucleus. The mass number of an atom tells you the total number of protons and neutrons in the nucleus.
Answer:
the speed at which something moves in a particular direction
Explanation:
The velocity of an object is the rate of change of its position with respect to a frame of reference, and is a function of time. ... Velocity is a physical vector quantity; both magnitude and direction are needed to define it.