Wednesday, April 29, 2009
What are the advantages and disadvantages of Science & Technology?
Advantages:
1)Science and technology can cure your diseases, provide shelter and food for crowds of people, enable the creation of large cities to allow collaboration in enterprises, and perhaps even more.
2)Computers - we can program these machines to do calculations not possible using a simple calculator nor by hand.
Disadvantages:
1)They can also entice you to sit in front of a TV (commonly called an idiot box) and fill you up with other peoples ridiculous ideas while your body slowly wastes away from lack of exercise.
2)often results in STRUCTURAL UNEMPLOYMENT (unemployment due to the way a business works, especially as technology improves and replaces humans doing work manually by hand).
Taken from :http://wiki.answers.com/Q/What_are_the_advantages_and_disadvantages_of_science_and_technology_in_life_span
http://answers.yahoo.com/question/index?qid=20081023001307AAO71XP
Advantages:
1)Science and technology can cure your diseases, provide shelter and food for crowds of people, enable the creation of large cities to allow collaboration in enterprises, and perhaps even more.
2)Computers - we can program these machines to do calculations not possible using a simple calculator nor by hand.
Disadvantages:
1)They can also entice you to sit in front of a TV (commonly called an idiot box) and fill you up with other peoples ridiculous ideas while your body slowly wastes away from lack of exercise.
2)often results in STRUCTURAL UNEMPLOYMENT (unemployment due to the way a business works, especially as technology improves and replaces humans doing work manually by hand).
Taken from :http://wiki.answers.com/Q/What_are_the_advantages_and_disadvantages_of_science_and_technology_in_life_span
http://answers.yahoo.com/question/index?qid=20081023001307AAO71XP
what we could have been, 7:11 AM.
Tuesday, April 28, 2009
1)How do you separate iron related material with a non-magnetic material in a mixture ?
The use of magnets. The magnets can attract the iron related material, separating it from the non-magnetic material.
This is an example of the use of magnets to separate mixtures .
2)When a solid dissolved in water , how can you separate the two ?
We can evaporate the water , once the water evaporates , the solid will be left. Example dissolving salt into water , evaporate the water, after that , only the salt is left.
3)How do we separate liquid and liquid?
Using Distallisation .
The use of magnets. The magnets can attract the iron related material, separating it from the non-magnetic material.
This is an example of the use of magnets to separate mixtures .
2)When a solid dissolved in water , how can you separate the two ?
We can evaporate the water , once the water evaporates , the solid will be left. Example dissolving salt into water , evaporate the water, after that , only the salt is left.
3)How do we separate liquid and liquid?
Using Distallisation .
what we could have been, 7:00 AM.
Monday, April 27, 2009
How do you separate mixtures ?
Here are some of the ways :
1) Filtration
Filtration is a mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases) by interposing a medium through which the fluid can pass, but the solids (or at least part of the solids) in the fluid are retained. It has to be emphasized that the separation is not complete, and it will depend on the pore size and the thickness of the medium as well as the mechanisms that occur during filtration.
2) Distillation
Distillation is the process of heating a liquid until it boils, capturing and cooling the resultant hot vapors, and collecting the condensed vapors.In the modern organic chemistry laboratory, distillation is a powerful tool, both for the identification and the purification of organic compounds. The boiling point of a compound—determined by distillation—is well-defined and thus is one of the physical properties of a compound by which it is identified. Distillation is used to purify a compound by separating it from a non-volatile or less-volatile material. When different compounds in a mixture have different boiling points, they separate into individual components when the mixture is carefully distilled.
3)Crystallization
Crystallization is a technique which chemists use to purify solid compounds. It is one of the fundamental procedures each chemist must master to become proficient in the laboratory. Crystallization is based on the principles of solubility: compounds (solutes) tend to be more soluble in hot liquids (solvents) than they are in cold liquids. If a saturated hot solution is allowed to cool, the solute is no longer soluble in the solvent and forms crystals of pure compound. Impurities are excluded from the growing crystals and the pure solid crystals can be separated from the dissolved impurities by filtration.
Reference taken by : www.wikipedia.com , http://orgchem.colorado.edu/hndbksupport/dist/dist.html , http://orgchem.colorado.edu/hndbksupport/cryst/cryst.html
Here are some of the ways :
1) Filtration
Filtration is a mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases) by interposing a medium through which the fluid can pass, but the solids (or at least part of the solids) in the fluid are retained. It has to be emphasized that the separation is not complete, and it will depend on the pore size and the thickness of the medium as well as the mechanisms that occur during filtration.
2) Distillation
Distillation is the process of heating a liquid until it boils, capturing and cooling the resultant hot vapors, and collecting the condensed vapors.In the modern organic chemistry laboratory, distillation is a powerful tool, both for the identification and the purification of organic compounds. The boiling point of a compound—determined by distillation—is well-defined and thus is one of the physical properties of a compound by which it is identified. Distillation is used to purify a compound by separating it from a non-volatile or less-volatile material. When different compounds in a mixture have different boiling points, they separate into individual components when the mixture is carefully distilled.
3)Crystallization
Crystallization is a technique which chemists use to purify solid compounds. It is one of the fundamental procedures each chemist must master to become proficient in the laboratory. Crystallization is based on the principles of solubility: compounds (solutes) tend to be more soluble in hot liquids (solvents) than they are in cold liquids. If a saturated hot solution is allowed to cool, the solute is no longer soluble in the solvent and forms crystals of pure compound. Impurities are excluded from the growing crystals and the pure solid crystals can be separated from the dissolved impurities by filtration.
Reference taken by : www.wikipedia.com , http://orgchem.colorado.edu/hndbksupport/dist/dist.html , http://orgchem.colorado.edu/hndbksupport/cryst/cryst.html
what we could have been, 6:40 AM.
Sunday, April 26, 2009
What are mixtures made up of ?
1. Liquid + Liquid
2. Liquid + Gas
3. Solid + Liquid + Gas
4. Solid + Solid
5. Solid + Liquid
6. Solid + Gas
7. Gas + Gas
1. Liquid + Liquid
2. Liquid + Gas
3. Solid + Liquid + Gas
4. Solid + Solid
5. Solid + Liquid
6. Solid + Gas
7. Gas + Gas
what we could have been, 6:57 AM.
Monday, April 20, 2009
what we could have been, 6:57 AM.
Thursday, April 16, 2009
Mixture
In chemistry, a mixture is when two or more different substances are mixed together but not combined chemically. The molecules of two or more different substances are mixed in the form of solutions, suspensions, and colloids.
While there are no physical changes in a mixture, the chemical properties of a mixture, such as its melting point, may differ from those of its components. Mixtures can usually be separated into its original components by mechanical means. Mixtures are either homogeneous or heterogeneous.
Mixtures are the product of a blending or mixing of chemical substances like elements and compounds, without chemical bonding or other chemical change, so that each ingredient substance retains its own chemical properties and makeup.
Examples of mixtures : Milk , dust , sea water .
Reference taken from : Wikipedia .
In chemistry, a mixture is when two or more different substances are mixed together but not combined chemically. The molecules of two or more different substances are mixed in the form of solutions, suspensions, and colloids.
While there are no physical changes in a mixture, the chemical properties of a mixture, such as its melting point, may differ from those of its components. Mixtures can usually be separated into its original components by mechanical means. Mixtures are either homogeneous or heterogeneous.
Mixtures are the product of a blending or mixing of chemical substances like elements and compounds, without chemical bonding or other chemical change, so that each ingredient substance retains its own chemical properties and makeup.
Examples of mixtures : Milk , dust , sea water .
Reference taken from : Wikipedia .
what we could have been, 7:39 AM.
Compounds
Chemical compounds are pure chemical substances consisting of two or more different chemical elements that cannot be separated into simpler substances and that have a unique and defined chemical structure. Chemical compounds consist of a fixed ratio of atoms that are hold together in a defined spatial arrangement by chemical bonds. Chemical compounds can be compound molecules hold together by covalent bonds, salts hold together by ionic bonds, metallic compounds hold together by metallic bonds, and complexes hold together by coordinate covalent bonds. Substances such as pure chemical elements and elemental molecules consisting of only a single atom type are not considered chemical compounds.
Examples of compounds are : water , table salt , sodium chloride .
Chemical compounds are pure chemical substances consisting of two or more different chemical elements that cannot be separated into simpler substances and that have a unique and defined chemical structure. Chemical compounds consist of a fixed ratio of atoms that are hold together in a defined spatial arrangement by chemical bonds. Chemical compounds can be compound molecules hold together by covalent bonds, salts hold together by ionic bonds, metallic compounds hold together by metallic bonds, and complexes hold together by coordinate covalent bonds. Substances such as pure chemical elements and elemental molecules consisting of only a single atom type are not considered chemical compounds.
Examples of compounds are : water , table salt , sodium chloride .
what we could have been, 7:31 AM.
