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**Frozen Ice Cube with Spike Phenomenon**

STATES OF MATTER

Anyone can pour liquid water into an ice tray and place it in a freezer (32 degrees F or 0 degrees C) to create a solid, known as ice. However, is it that easy to create an //ice spike//? Pictured above is one of these fascinating spikes protruding from an ice cube. Due to the water initially freezing around the edges of the cube, there is a center hole that is occasionally not frozen right away. As volume expands in the ice cube holder, water is pushed up through this unfrozen center hole. The liquid turns to solid as it comes in contact with the cold air. The most important concept to understand in order to generate this unique icicle-like characteristic is water’s solid state of matter. Water has the ability to take 3 forms of matter: solid as ice, liquid as water, and gas as steam. In most substances, when temperature decreases, the molecules compact and density increases. However, water has a distinct property of having hydrogen bonding. This means that when water freezes, the liquid takes in oxygen due to complex hydrogen bonding (as shown in the picture below). As a result, the solid ice cubes are more voluminous and less dense than the liquid. In particular, the water freezes around the outer surface first before solidifying the center liquid. As the ice slowly freezes around the edges, a small hole is left thawed in the surface. Since, as explained before, water expands as it freezes, the ice freezing under the surface pushes up through that hole. With proper frosty conditions, the water coming out from the cube will freeze as it moves up through the hole. This will create the desired ice spike phenomenon. A helpful diagram is displayed below. Thermodynamics When the water freezes as it extends from the icy surface, thermodynamic concepts act upon the ice cube. In order for liquid water to freeze, energy (heat) had to be removed. This is called the enthalpy of fusion. By removing heat from the water, the cold air in the freezer or other freezing machine takes that heat and allows the liquid to gain coldness. As the ice tray reacts to the temperatures in the cold box, thermal communication occurs between the two objects. As a result, they reach thermal equilibrium with one another, meaning they reach the same temperature. This finally creates an ice cube, or an ice cube with an ice spike attachment.

Mass (Conservation of) Even with a skewer connected to the ice cube, the mass of the ice cube is the same as the mass of the water originally poured into the tray. The law stating that sum of all the forms of energy and mass in the universe is a certain amount, which remains constant, is a comprehensive application. Though ice contains less energy than water, considering energy was withdrawn to change the state of matter, both materialistic states contain equal amounts of molecules. At the exact moment before melting, the average kinetic energy of the ice molecules is the same as the average kinetic energy of the water molecules at the exact moment after melting. * In case you are unfamiliar with some of the terms used: *  1. thermal communication = when two objects of different temperatures come into contact and, therefore, alter their temperatures  2. thermal equilibrium = when two objects reach the same temperature (usually after thermal communication)  3. thermodynamics = study branch of physical science that deals with heat and other energy forms Sources Libbrecht, Kenneth G. “Ice Spikes.” //Snow Crystals//. N.p., 1 Feb. 1999. Web. 18 Dec. 2011. . “Principles of Thermodynamics.” //The New Encyclopaedia Britannica//. Ed. Jacob E Safra and Jorge Aguilar-Cauz. 15th ed. Vol. 28. Chicago: Encyclopaedia Britannica, 2005. 619-20. Print. Serway, Raymond A., et al., eds. //Physics//. Austin: Holt, Rinehart, and Winston, 2002. Print. PICTURES LINKED TO ORIGINAL SOURCE
 * Physics Topic Categories:** Mass Heat States of Matter