Ponto de Fusão e Ebulição - diferentes substâncias em diferentes estados físicos

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O Incrível Pontinho Azul

Olá pequenos cientistas! Falamos sobre os estados físicos da matéria e suas transformações, mas as s...

Video Transcript:

Hello, little scientists, I am Professor Bill Tyson and together we are going to know different forms of science. In our last meeting we talked about the physical transformations of matter. Today we are going to talk about the temperature at which the solid substances become liquid and the liquid substances become gaseous.

In nature we find several types of substances in different states, for example the oxygen we breathe is in the gaseous state. The water we drink is in the liquid state and a metal fork that we use to eat is in a solid state. But why are they in different states if they are in an environment under the same temperature?

We call this the melting point, and the boiling point. The boiling point is when a substance passes from the liquid to the gaseous state, it is called so because when the liquid is very heated it starts to make bubbles, then boiling. Each chemical element has its property, its melting point and boiling point.

That is, a specific temperature changes the state of matter of a solid, liquid or gaseous substance. Water for example. For it to turn ice, it must be at a temperature of zero degrees celsius.

This temperature is then the melting point of the water. For the water to turn gas, steam must be at a temperature of 100 degrees celsius. And this temperature is the boiling point of the water.

If a substance is found in nature in the gaseous state, it will need a much lower temperature to pass into the liquid state. Oxygen for example, its melting point is 218 degrees Celsius below zero, or 218 degrees Celsius negative. This is the temperature required for oxygen to turn liquid.

And in the case of a substance that we find in nature in the solid state? What is the temperature to become liquid? Iron, for example, has its melting point at 1538 degrees celsius.