Does there exist a fourth state of matter? What is that?
Yes, the fourth state of matter is called plasma.
Plasma:
At a very high temperature, the collision between atoms a molecule tears off their actions. Atoms become positive ions. The ionic state of matter is called the plasma-the fourth state of matter.
What is meant by density? What is its SI unit?
Density:
The density of a substance is defined as its mass per unit volume.
Density =$\frac{(Mass of a substance)}{(volume of the substance)}$
OR
D=$\frac{m}{v}$
Unit of Density:
SI unit of density is kilogram per cubic meter $kgm^{-3}$).
How the kinetic molecular model of matter helps differentiate various states of matter?
Kinetic Molecular Model of Matter:
Characteristics of Molecular Model of Matter:
The kinetic molecular model is used to explain the three states of matter - solid, liquid, and gas.
a. Solids:
b Liquids:
c. Gases:
d. Plasma – The fourth state of matter:
1. Production/Formation of Plasma:
The kinetic energy of gas molecules goes on increasing if a gas is heated continuously. This causes the gas molecules to move faster and faster. The collisions between atoms and molecules of the gas become so strong that they tear off the atoms. Atoms lose their electrons and become positive ions. This ionic state of matter is called plasma. Plasma is also formed in gas discharge tubes when an electric current passes through these tubes.
2. Plasma is called the fourth state of matter in which a gas occurs in its ionic state. Positive ions and electrons get separated in the presence of electric or magnetic fields.
3. Plasma also exists in neon and fluorescent tubes when they glow.
4. Most of the matter that fills the universe is in the plasma state.
5. In stars such as our Sun, gases exist in their ionic state.
6. Plasma is a highly conducting state of matter. It allows electric current to pass through it.
Density of various substance |
|
Substances |
Density in $kgm^{-1}$ |
Air |
1.3 |
Foam |
89 |
Petrol |
800 |
Cooking Oil |
920 |
Ice |
920 |
Water |
1000 |
Glass |
2500 |
Aluminum |
2700 |
Iron |
7900 |
Copper |
8900 |
Lead |
11200 |
Mercury |
13600 |
Gold |
19300 |
Platinum |
21500 |
1 metre cube (1 m3) = 1000 litre
1 litre = $10^{-3}$
1 cm3 = $10^{-6}$
1000 $kgm^{-3}$ = 1 $gcm^{-3}$