A. The molecules of solids are close together and compact, liquids are spread out but not too far apart, and gas molecules are really far apart.
B. Increase in temperature causes pressure to go up. Decrease in temperature cause pressure to go down
Answer:
When <em>a scientist on Earth drops a hammer and a feather at the same time an astronaut on the moon drops a hammer and a feather, the result</em> expected is that <em>the hammer hits the ground before the feather on Earth, and the hammer and feather hit at the same time on the moon (option D).</em>
Explanation:
In the abscence of atmosphere (vacuum), the objects fall in free fall. This is, the only force acting on the objects is the gravitational pull, which is directed vertlcally downward.
Under such absecence of air, the equations that rules the motion are:
- V = Vo + gt
- d = Vo + gt² / 2
- Vf² = Vo² + 2gd
As you see, all those equations are independent of the mass and shape of the object. This explains why <em>when an astronaut on the moon drops a hammer and a feather at the same time</em>, <em>the hammer and feather hit at the same time on the moon</em>, a space body where the gravitational attraction is so small (approximately 1/6 of the gravitational acceleration on Earth) that does not retain atmosphere.
On the other hand, the air (atmosphere) present in Earth will exert a considerable drag force on the feather (given its shape and small mass), slowing it down, whereas, the effect of the air on the hammer is almost neglectable. In general and as an approximation, the motion of the heavy bodies that fall near the surface is ruled by the free fall equations shown above, so, <em>the result </em>that is<em> expected when a scientist on Earth drops a hammer and a feather at the same time is that the hammer hits the ground before the feather</em>.
Chemical,when you light a match stick, you are starting a chain reaction of the substance chemical formula, making it a chemical change
<span>Cellular respiration is the chemical reaction in which glucose and oxygen are turned into water, carbon dioxide, and energy. Now you know the answer. :P</span>
