This quick video explains what is meant by specific heat or heat capacity. It shows how common substances sand and water absorb heat at different rates.
Finally, we get to see this in action with a cool experiment at the end. Specific heat is the amount of energy in Joules that is needed to raise the temperature of a substance by one degree Celsius. Water has the highest specific heat of any liquid. It requires 4. This is the most energy required to raise a liquid by one degree.
Water's high specific heat is very useful to life. If water did not have such a high heat capacity, the temperature of Earth would change violently with the changing of day to night. The oceans would become frigid at night and boil during the day. This world would be very difficult to survive in. Thankfully, a lot of energy is needed to change the temperature of water and we can enjoy a nice, cool ocean or lake even on the hottest summer day.
Image source: By Flickr CC0 , via pexels. Water has a bizarrely high specific heat in general, it's the highest of all liquids due to hydrogen bonding between molecules. The specific heat is the amount of heat needed to raise a gram of water by one degree Celsius. Image source: By unknown author CC0 , via pxhere.
When heat energy is absorbed by water, the hydrogen bonds begin to break and the freed water molecules can move. This means that water can absorb heat energy before changing temperatures. The energy goes into breaking hydrogen bonds. It takes a lot of energy to make water increase in temperature. Credit: Wikimedia. Water has a high specific heat, meaning it takes more energy to increase the temperature of water compared to other substances. This is why water is valuable to industries and in your car's radiator as a coolant.
The high specific heat of water also helps regulate the rate at which air changes temperature, which is why the temperature change between seasons is gradual rather than sudden, especially near the oceans. This same concept can be expanded to a world-wide scale. The oceans and lakes help regulate the temperature ranges that billions of people experience in their towns and cities.
Water surrounding or near cities take longer to heat up and longer to cool down than do land masses, so cities near the oceans will tend to have less change and less extreme temperatures than inland cities. This property of water is one reason why states on the coast and in the center of the United States can differ so much in temperature patterns.
A Midwest state, such as Nebraska, will have colder winters and hotter summers than Oregon, which has a higher latitude but has the Pacific Ocean nearby. If you leave a bucket of water outside in the sun in summer it will certainly get warm, but not hot enough to boil an egg. But, if you walk barefoot on the black asphalt of a street in the southern portion of the United States in August, you'll burn your feet.
Dropping an egg on the metal of my car hood on an August day will produce a fried egg. Metals have a much lower specific heat than water. If you've ever held onto a needle and put the other end in a flame you know how fast the needle gets hot, and how fast the heat is moved through the length of the needle to your finger.
Not so with water. The high specific heat of water has a great deal to do with regulating extremes in the environment. For instance, the fish in this pond are happy because the specific heat of the water in the pond means the temperature of the water will stay relatively the same from day to night. They don't have to worry about either turning on the air conditioner or putting on their woolen flipper gloves. Also, for happy fish, check out our page on Dissolved Oxygen.
Lucky for me, you, and the fish in the pond to the right, water has a higher specific heat than many other substances. For water, this amount is one calorie, or 4. As a result, it takes water a long time to heat and a long time to cool.
In fact, the specific heat capacity of water is about five times more than that of sand. This explains why the land cools faster than the sea.
The resistance to sudden temperature changes makes water an excellent habitat, allowing organisms to survive without experiencing wide temperature fluctuation.
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