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? 發問於 科學及數學其他 - 科學 · 1 十年前

# 有2條問題想問 用英文答 20marks

1. Do you think there is only three states(solid,lique,gas) of matter ?

(Is it semi-solid)

2.when you squeeze a sponge , its volume seems to decrease ,do you think a sponge is solid? why?

### 2 個解答

• 1 十年前
最愛解答

A1:

Everything on Earth can be explained in terms of 4 states (phases) of matter-- solid, liquid, gas, and plasma.

&lt; Solid &gt;

A substance in a solid phase is relatively rigid, has a definite volume and shape.

The atoms or molecules that comprise a solid are packed close together and are not compressible.

Because all solids have some thermal energy, its atoms do vibrate. However, this movement is very small and very rapid, and cannot be observed under ordinary conditions.

&lt; Liquid &gt;

Liquids have a definite volume, but are able to change their shape by flowing.

Liquids are similar to solids in that the particles touch. However the particles are able to move around.

Since particles are able to touch the densities of liquid will be close to that of a solid.

Since the liquid molecules can move they will take the shape of their container.

&lt; Gas &gt;

Gases have no definite volume or shape. If unconstrained gases will spread out indefinitely. If confined they will take the shape of their container. This is because gas particle have enough energy to overcome attractive forces. Each of the particles are well separated resulting in a very low density.

&lt; Plasma &gt;

The fourth state of matter is plasma. Plasma is an ionized gas, a gas into which sufficient energy is provided to free electrons from atoms or molecules and to allow both species, ions and electrons, to coexist. In effect a plasma is a cloud of protons, neutrons and electrons where all the electrons have come loose from their respective molecules and atoms, giving the plasma the ability to act as a whole rather than as a bunch of atoms. Plasmas are the most common state of matter in the universe comprising more than 99% of our visible universe and most of that not visible. Plasma occurs naturally and makes up the stuff of our sun, the core of stars and occurs in quasars, x-ray beam emitting pulsars, and supernovas. On earth, plasma is naturally occurring in flames, lightning and the auroras. Most space plasmas have a very low density, for example the Solar Wind which averages only 10 particles per cubic-cm. Inter-particle collisions are unlikely - hence these plasmas are termed collisionless.

A2:

Although a sponge&#39;s volume seems to decrease when you squeeze it, the actual shapes and volumes of the sponge units do not change. Only the gas(es) and the liquid(s) between the sponge units are squeezed out. So, by definition that a solid has a definite volume and shape, a sponge is a solid.

• 1 十年前

Q1. For H2O, yes. There is only three states of H2O (this compound).

Q2. Sponge os solid. However, it has a ability to absorb of liquid as it has many spores in between.

資料來源： my knowledge