<span>carrying twice the weight and climbing twice as high</span>
Answer:
There are no gaps in space between the photons as they travel. If you were to look at a wave then you'd come to a conclusion that indeed that there aren't any gaps unless they are specifically placed.The light from a distance star indeed spreads out and weakens as it travels, but this just reduces the wave strength and does not introduce gaps.
Answer:
both kinetic energy and potential energy
Answer:
The slope of a position-time graph can be calculated as:

where
is the increment in the y-variable
is the increment in the x-variable
We can verify that the slope of this graph is actually equal to the velocity. In fact:
corresponds to the change in position, so it is the displacement, 
corresponds to the change in time
, so the time interval
Therefore the slope of the graph is equal to

which corresponds to the definition of velocity.
Answer:
Two oxygen atoms
Explanation:
The majority of the oxygen in the air in our atmosphere consists of molecular oxygen (
), which consists of 2 atoms of oxygen, since free oxygen mainly form covalent bonds with other atoms of oxygen.
A small fraction of the oxygen, however, in the ozone form, which consists of 3 atoms of oxygen bond together (
).