The Correct answer: 18
They are also known as families because they are in the same column.
The absence of external force in the outer space, allows the piece of rock to continue moving at the same velocity for thousands of years.
<h3>Absence of external force on the outer space</h3>
The outer space is almost an absolute vacuum, because it's nearly empty. There is no matter such as air in the outer space that will provide an external force needed to change the velocity of the piece of rock.
From Newton's first law of motion, an object in a state of rest or uniform motion in a straight line, will continue in that state unless it is acted upon by an external force.
Thus, the absence of external force in the outer space, allows the piece of rock to continue moving at the same velocity for thousands of years.
Learn more about outer space here: brainly.com/question/24701339
There can be many species in an ecosystem some consume more energy than others
For energy released from vaporisation,
Q(Energy) = m(mass of vapour) X l (latent heat of vaporisation)
= (0.65) X (2257)
