<span>D. Atoms of all elements contain protons, but the number of protons is different for every element.
</span>
Answer:
Muscle contraction thus results from an interaction between the actin and myosin filaments that generates their movement relative to one another. The molecular basis for this interaction is the binding of myosin to actin filaments, allowing myosin to function as a motor that drives filament sliding.
Answer:

Explanation:
The torque applied by a force can be calculated as

where
F is the magnitude of the force
d is the length of the arm
is the angle between the direction of the force and the arm
In this problem, we have
F = 15 N
d = 2.0 m

Substituting into the equation, we find

Answer:
The column number tells us the amount of valence electron the element has
<h2>
Answer: It is highly flammable.</h2>
Explanation:
Liquid oxygen is created from oxygen atoms that have been forced to assume the liquid state due to <u>compression (change of pressure) and temperature modification.
</u>
Specifically this is achieved by cooling the oxygen enough to change it to its liquid state. So,<u> as the temperature drops, the atoms move more slowly because they have less energy.
</u>
In this sense, in the liquid state it is easier to store and mobilize oxygen, taking into account that it is a highly flammable gas.