Matter

Slide 1: 

Matter By- Ruchii Sheth, VIII-B, Roll no:23

What is matter? : 

What is matter? Matter is a general term for the substance of which all physical objects are made. Typically, this includes atoms and other particles which have mass . However in practice there is no single correct scientific meaning; each field uses the term in different and often incompatible ways. A common way of defining matter is as anything that has mass and occupies volume.

Properties of matter : 

Properties of matter

Chemical properties : 

Chemical properties Chemical properties describe the way a substance can change or react to form other substances. These properties, then, must be determined using a process that changes the identity of the substance of interest.

Comparison of chemical and physical properties : 

Comparison of chemical and physical properties

What is Substance ? : 

What is Substance ? Substances can be identified as either an element, compound, or a mixture.

What is a pure substance? : 

What is a pure substance? Compounds Can be decomposed into simpler substances by chemical changes, always in a definite ratio Elements Cannot be decomposed into simpler substances by chemical changes

Mixtures : 

Mixtures Mixtures are two or more substances that are NOT chemically combined. Mixtures do not: ·      Have constant boiling points ·      Have constant melting points

Homogenous mixtures : 

Homogenous mixtures Homogenous mixtures look the same throughout but can be separated by physical means (dissolution, centrifuge, gravimetric filtering, etc.). Examples: milk, yogurt

Heterogeneous mixtures : 

Heterogeneous mixtures Heterogeneous mixtures are composed of large pieces that are easily separated by physical means (i.e.. density, polarity, metallic properties).

What are solutions ? : 

What are solutions ? Solutions are homogenous mixtures that do not scatter light. These mixtures are created when something is completely dissolved in pure water. Therefore, they are easily separated by distillation or evaporation. Examples: sugar water, salt water

Slide 12: 

Solid, Liquid, Gases and Plasma

Types of matter : 

Types of matter Solid Liquid Gases Plasma

Solid : 

Solid Have a definite shape Have a definite volume Kinetic Molecular Theory Molecules are held close together and there is very little movement between them.

Liquid : 

Liquid Have a definite volume Have an indefinite shape Kinetic Molecular Theory: Atoms and molecules have more space between them than a solid does, but less than a gas (i.e.. It is more “fluid”.)

Gases : 

Gases Have an indefinite shape Have an indefinite volume Kinetic Molecular Theory: Molecules are moving in random patterns with varying amounts of distance between the particles.

Slide 18: 

At 100°C, water becomes water vapor, a gas. Molecules can move randomly over large distances. Between 0°C and 100 °C, water is a liquid. In the liquid state, water molecules are close together, but can move about freely. Below 0°C, water solidifies to become ice. In the solid state, water molecules are held together in a rigid structure.

Plasma : 

Plasma Plasma is by far the most common form of matter. Plasma in the stars and in the tenuous space between them makes up over 99% of the visible universe and perhaps most of that which is not visible. On earth we live upon an island of "ordinary" matter. The different states of matter generally found on earth are solid, liquid, and gas. We have learned to work, play, and rest using these familiar states of matter. Sir William Crookes, an English physicist, identified a fourth state of matter, now called plasma, in 1879.

Slide 20: 

Star formation in the Eagle NebulaSpace Telescope Science Institute, NASA (below) (Above) X-ray view of Sun from Yohkoh, ISAS and NASA

Slide 21: 

Thank you