Lithium has an atomic number of 3 so right away all the answer choices are eliminated except A., and oxygen does have 8 neutrons, boron 5 electrons, and neon a mass of 20
Answers:
a) 
b) 
c) 
Explanation:
<h3>a) Mass of the continent</h3>
Density
is defined as a relation between mass
and volume
:
(1)
Where:
is the average density of the continent
is the mass of the continent
is the volume of the continent, which can be estimated is we assume it as a a slab of rock 5300 km on a side and 37 km deep:

Finding the mass:
(2)
(3)
(4) This is the mass of the continent
<h3>b) Kinetic energy of the continent</h3>
Kinetic energy
is given by the following equation:
(5)
Where:
is the mass of the continent
is the velocity of the continent
(6)
(7) This is the kinetic energy of the continent
<h3>c) Speed of the jogger</h3>
If we have a jogger with mass
and the same kinetic energy as that of the continent
, we can find its velocity by isolating
from (5):
(6)
Finally:
This is the speed of the jogger
DNA database was established in 1995
Gate-control theory
<h3>What is Gate-control theory?</h3>
According to the Gate Control Theory of Pain, the spinal cord has a system that allows pain signals to be amplified in the brain before being processed at the spinal cord itself, or attenuated there.
The mechanism that allows or prevents the passage of pain signals is known as the gate. The gate may be open or it may be closed, one of two possibilities:
- When the gate is open, pain signals can enter and are delivered to the brain, where they are perceived as pain.
- If the gate is closed, pain signals will be prevented from ascending to the brain and won't be felt.
The administration of a non-noxious (soothing or light rubbing) stimulus can help engage the gate control mechanism and alleviate pain in those who are exposed to painful (noxious) stimuli.
Learn more about gate-control theory here:
brainly.com/question/15561467
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