It is covalent bonding. The electrons are shared between the phosphorus and the chlorines.
covalent bonding is when electrons are shared between two elements.
molecular polarity is a little bit complicated, but I will try to explain ;)
PCl3 is an alternation on tetrahedral molecules.
It means that P has one lone pair of electrons. This pair of electrons are only attracted to the P nuclei and thus a greater freedom of motion.
This means that their orbital is bigger and this pushes the 3 Cl atoms closer together.
The angle between each Cl now is 107 and the angle between Cls and P is greater than 107.
Now, due to this shape, and also electronegativity (Cl is more electronegative than P meaning that it tends to hog the electrons they share closer to itself), PCl3 is polar. Electrons that are shared tend to flow closer towards the Cl than the P side.
Therefore, on the Cl side of the molecule it's, more negative. On the P side, it's more positive.
Answer:The earths plates shifting
Explanation: The movement releases stored-up 'elastic strain' energy in the form of seismic waves, which propagate through the Earth and cause the ground surface to shake.
La energía térmica es la energía que proviene del calor.
De nada ;)

What is the difference between a quantity and a unit?
Answer:
Physical quantities are a characteristic or property of an object that can be measured or calculated from other measurements. Units are standards for expressing and comparing the measurement of physical quantities. All units can be expressed as combinations of four fundamental units.
Hope this helps!!!

I think the answer is c. two molecules