It is theoretically possible for a substance to have a negative value of cubical expansivity, which means that the substance would contract rather than expand when the temperature increases. However, it is very rare for a substance to have a negative value of cubical expansivity over a significant range of temperatures.
One example of a substance that has a negative value of cubical expansivity over a limited range of temperatures is water. Water has a positive value of cubical expansivity at...
Yes, a vector which has zero magnitude is also a vector in case of two vectors travelling in opposite directions with equal magnitudes. At this case, the resultant vector has zero magnitude but it is still a vector. We call it a null vector.
First learn basic HTML, then CSS and responsive CSS for Static websites and thereafter JavaScript and PHP for dynamic pages. If you also want to learn jQuery for more better works learn it at the same time with JavaScript

The Rh factor(the Rhesus factor or Rh antigen), is a protein that can be found on the surface of red blood cells. It is one of the most important blood group systems in human blood typing. The presence or absence of the Rh factor is denoted as either Rh-positive (+) or Rh-negative (-).
Fun fact: The Rh factor is named after the Rhesus monkey, in which the protein was first discovered.