What unusual property of water is responsible for frost wedging?

The property of water that it expands and becomes less dense as it freezes. The property is unusual because it  is not the case in other liquids. 
 Ice wedging is a form of mechanical weathering or physical weathering in which cracks in rock or other surfaces fill with water, freeze and expand, causing the cracks to enlarge and eventually break.

1. The fact that water requires more volume when it solidifies (freezes). Most liquids will turn into a solid when they freeze and in the process of freezing, take a smaller volume. But water is unusual in that when it freezes, it increases its volume. And during that expansion, it can exert a LOT of force. If water is in an enclosed space, it can exert about 1000 times atmospheric pressure against its surroundings.

The answer is c. 320 g

Following are the  advantages of the parametric equations: 1) they can be used to graph curves that are not functions, like the unit circle.2) the parameter can be used to represent the quantity that is  useful to  provide us with better information about the graph.3)  it is useful to convert between rectangular equations and parametric equations.with specific reference to chemistry,  parametric equations are employ for solving hydrogen and hydrogen-like ions, quantum mechanically. herein, cartesian coordinates are converted in spherical polar coordinates. the solution obtained, when plotted on spherical polar graph paper, provides visualization of atomic orbital such as s,p,d and f.