Answer:
The answer would either be Carbon or Silicon.
Explanation:
The average weight of an atom of an element, formerly based on the
weight of one hydrogen atom taken as a unit or on 1/16 (0.0625) the
weight of an oxygen atom, but after 1961 based on 1/12 the weight of the
carbon-12 atom.
In gas the speed of sound is 343.2 meters per second, in liquid the speed of sound is 1,484 meters per second and in solids like steel it travels 5,120 meters per second.
An open system is
when there is a transfer of energy and matter with its surroundings.
A closed system is
where there is a transfer of energy, may it be heat or work, but not matter
with its surroundings.
An isolated system
is where there is no transfer of energy or matter with its surroundings.