When liquids are subjected to lower temperatures, the kinetic energy of the molecules would decrease accordingly making them closer to each other and leading to a decrease in volume until the substance is solidified. Hope this answers the question.
Atomic number The atomic number of each element is different than other Elements.
Because in CH4 the valence electrons of Carbon are being pulled away from the nucleus with the same force (since all hydrogen has the same electronegativity).So charges are equally distributed throughout the atom and the atom is non-polar. In CH3Cl Cl has a different electronegativity than H, so charges aren't equally distributed and therefore the molecule is polar.
<span>A SI base unit is the single and direct measurement unit for a physical entity. E.g. For mass it is kg, for time it is sec, A derived unit is determined by a physical equation with the base units, like for velocity equals distance divided by time, in SI units: unit of v (velocity)= m (meter) divided by sec (seconds).
Hope this helps!</span>
