Thursday, March 17, 2011

na nie ~ copy from website utk syg sye :D and i use to my hw too :D

Apabila kerajaan mula mengisytiharkan Tahun Melawat Malaysia pada tahun 1990, usaha ini menunjukkan bahawa kerajaan semakin memberikan perhatian yang serius kepada industri pelancongan kerana langkah ini berpotensi memajukan ekonomi negara. Setiap tahun bilangan pelancong yang datang ke Malaysia semakin meningkat. Persoalannya, apakah kebaikan yang diperoleh negara dalam usaha mempromosikan negara yang kita cintai ini, iaitu Malaysia kepada pelancong dari negara luar.

Satu daripada kebaikan sektor pelancongan negara ialah kita
dapat memperkenalkan negara Malaysia ke seantero dunia. ( Ayat topik ) Misalnya, melalui kejohanan perlumbaan kereta Formula 1 di litar Sepang, Sukan Komanwel 1998, kita dapat mempopularkan negara kita dalam kalangan peminat sukan dunia. Selain itu, kita dapat membuktikan bahawa kita mampu menjadi tuan rumah bagi sukan berprestij dunia yang lengkap dengan pelbagai kemudahan prasarana. Slogan ‘’Malaysia Boleh’’ telah membuktikan keupayaan negara kita dalam penganjuran sukan yang bertaraf antarabangsa tersebut. Melalui penganjuran Kejohanan F1, Malaysia dapat dipromosi ke seluruh dunia dengan kos yang rendah melalui siaran langsung kejohanan tersebut ke seluruh dunia. Ini membuktikan bahawa tarikan penganjuran sukan bertaraf dunia bukan sahaja menggalakkan kedatangan pelancong ke negara kita bahkan dapat mempromosi Malaysia kepada dunia luar secara meluas dengan kos yang minima bertepatan dengan maksud peribahasa, ”Sambil Menyelam Minum Air”.
Seterusnya, sektor pelancongan juga dapat meningkatkan ekonomi negara dari segi pengaliran wang asing masuk ke negara kita. (Ayat topik). Pelancong yang datang dari negara luar terpaksa menukar mata wang negara mereka kepada mata wang Ringgit Malaysia sebelum boleh berbelanja di sini. Ini dapat dilakukan sama ada di bank tempatan mahupun di pusat pertukaran mata wang asing. Mata wang asing ini kemudian disimpan untuk digunakan ketika membiayai perbelanjaan mengimport barang dari luar negara. Peniaga mata wang asing juga mendapat keuntungan daripada pernigaan yang dijalankan. Pengaliran masuk mata wang asing ke negara kita bukan sahaja menguntungkan entiti perniagaan bahkan dapat digunakan untuk membeli barangan keperluan asas untuk rakyat tempatan dari luar negara.
Sektor pelancongan dapat memajukan industri kraftangan di Malaysia. ( Ayat topik ). Barangan kraftangan buatan rakyat tempatan bukan sahaja bermutu bahkan harga yang ditawarkan amat berpatutan. Barangan kraftangan buatan rakyat Malaysia yang diperbuat daripada kain batik, seramik, kayu, perak, kaca dan kulit amat cantik dari segi reka bentuk dan sesuai dijadikan cenderahati kepada pelancong. Pelancong pasti membeli-belah barangan kraf tangan buatan Malaysia seperti batik, kain songket, dan lain-lain sebagai buah tangan atau ole-ole buat keluarga atau rakan mereka. Kedatangan pelancong asing ke Malaysia bukan sahaja memajukan industri kraf tangan ke luar negara kita bahkan menjadi periuk nasi kepada pengusaha kraftangan tempatan.
Sektor pelancongan dapat memajukan bidang perniagaan di Malaysia. Pelancong asing yang datang ke Malaysia memerlukan tempat penginapan, makanan dan minuman, perkhidmatan pengangkutan, juru pandu pelancong dan perkhidmatan lain. Pelancong asing amat menggemari makanan sama ada makanan tradisonal mahu pun makanan barat di Malaysia. Mereka diberi pilihan yang amat banyak sama ada menikmati makanan di hotel bertaraf lima bintang, medan selera yang besar dan berhawa dingin mahupun di kedai dan warung yang terletak di tepi jalan. Mereka juga boleh menikmati hidangan makanan laut di restoran yang didirikan secara terapung di atas air. Sambil menikmati makanan, mereka dapat menghirup panorama yang amat cantik dan menghirup udara segar di tepi laut. Permintaan yang tinggi terhadap makanan ini mewujudkan peluang perniagaan yang luas kepada usahawan tempatan. Pusat-pusat penginapan juga giat dibina bagai cendawan tumbuh selepas hujan di kawasan peranginan seperti di pulau dan tepi pantai. Pelancong asing diberi pilihan untuk menginap di hotel bertaraf lima bintang, resort atau menginap secara pakej seperti ”Eco-Tuorism” yang membolehkan pelancong asing menginap di rumah kampung dan mempelajari cara hidup masyarakat termasuk cara berpakaian, makanan tradisional dan sebagainya. Pelancong juga memerlukan perkhidmatan pengangkutan untuk bergerak dari satu lokasi pelancongan ke lokasi yang lain. Ini membolehkan pengusaha bidang pengangkutan seperti bas, teksi, van, bot, feri dan lain-lain mendapat peluang untuk menjalankan perniagaan. Tidak dinafikan peluang yang datang memberi rezeki yang melimpah ruah kepada peniaga yang ringan tulang.

Sektor pelancongan dapat memperkenalkan budaya Malaysia yang unik lagi istimewa kepada dunia luar. Hal ini demikian kerana Malaysia mempunyai penduduk yang berbilang kaum dan etnik seperti Melayu, Cina, India, Kadazan, Murut, Iban dan lain-lain. Kaum-kaum di negara kita yang mempunyai adat, budaya dan cara pemakanan yang berbeza dan istimewa mampu menarik minat pelancong asing. Selain itu, sektor pelancongan dapat mempromosikan warisan budaya yang tak lapuk dek hujan dan tak lekang dek panas ke serata dunia. Pelancong yang datang ke suatu destinasi pelancongan boleh dihidangkan dengan persembahan kesenian tradisional misalnya wayang kulit, makyung, dikir barat, ronggeng dan kuda kepang. Mereka juga diberi peluang untuk mencuba permainan tradisional seperti sepak raga, galah panjang, congkak, batu seremban dan lain-lain. Pakaian tradisional seperti baju kurung yang diperbuat daripada kain batik dan songket boleh cuba dipakai oleh pelancong asing. Keseronokan pengalaman yang dibawa pulang ke negara asal pelancong akan menjadi memori indah yang akan menggamit mereka untuk datang semula ke negara kita. Keunikan budaya masyarakat Malaysia yang berjaya dipromosi melalui sektor pelancongan sebenarnya memberi imej yang sangat baik kepada negara Malaysia.
Akhir kalam, industri pelancongan banyak memberikan sumbangan yang besar terutama dari segi ekonomi kepada negara kita. Oleh itu, semua pihak haruslah bekerjasama bagai aur dengan tebing untuk mempromosikan Malaysia di mata dunia kerana tak kenal maka tak cinta.

Tuesday, March 15, 2011

Some Revive About Chemistry form 4~

italian physicist Amedeo Avogadro (Name at birth: Lorenzo Romano Amedeo Carlo Avogadro)
  • Born: 9 August 1776
  • Birthplace: Turin, Piedmont, Italy
  • Died: 9 July 1856
  • Best Known As: The guy they named Avogadro’s number after
1. Avogadro constant / Avogadro’s number is 6.02 x 1023
2. Atomic substances
  • Elements – all the particles are atoms.
  • Example: zinc (Zn), sodium (Na), aluminium (Al) and all noble gases, argon (Ar), helium (He) and neon (Ne).
  • RAM (Relative Atomic Mass) of  Na = 23
3. Molecular substances
  • Covalent compounds – the particles are molecules.
  • Example: carbon dioxide (CO2), water (H2O) and non-metal elements, iodine (I2), nitrogen (N2) and oxygen (O2).
  • RMM (Relative Molecular Mass) of I2 = 127 + 127 = 254
4. Ionic substances
  • Ionic compounds – the particles are ions.
  • Example: sodium chloride (NaCl), hydrochloric acid (HCl) and potassium iodide (KI).
  • RFM (Relative Formula Mass) of HCl = 1 + 35.5 = 36.5
5. Avogadro’s Law / Gas Law states that equal volumes of all gases contain the same number of molecules under the same temperature and pressure.
  • Example: equal volumes of molecular hydrogen and nitrogen would contain the same number of molecules under the same temperature and pressure.
6. Volume of gas (dm3) = Number of moles of gas x Molar volume
7. Room temperature and pressure (r.t.p.) = 24 dm3 mol-1 (25°C and 1 atm)
  • Example: What is the volume of 5.0 mol helium gas at s.t.p.?
  • Volume of gas = Number of moles x Molar gas volume
    = 5.0 mol x 24 dm3 mol-1
    = 120 dm3
8. Standard temperature and pressure (s.t.p.) = 22.4 dm3 mol-1 (0°C and 1 atm)
  • Example: What is the volume of 5.0 mol helium gas at s.t.p.?
  • Volume of gas = Number of moles x Molar gas volume
    = 5.0 mol x 22.4 dm3 mol-1
    = 112 dm3
9. Mass (g) = Number of moles x Molar mass
10. Number of particles = Number of moles x Avogadro constant
11. Volume (dm3) = Number of moles x Molar volume

Thursday, March 10, 2011

Chemistry??? What is Chemistry.. i tell U :D

What is Chemistry? - Chemistry is the study of the composition, structure, properties and interactions of matter.
 



In retrospect, the definition of chemistry seems to invariably change per decade, as new discoveries and theories add to the functionality of the science. Shown below are some of the standard definitions used by various noted chemists:

Alchemy (330) – the study of the composition of waters, movement, growth, embodying and disembodying, drawing the spirits from bodies and bonding the spirits within bodies (Zosimos).
Chymistry (1661) – the subject of the material principles of mixt bodies (Boyle).
Chymistry (1663) – a scientific art, by which one learns to dissolve bodies, and draw from them the different substances on their composition, and how to unite them again, and exalt them to an higher perfection (Glaser).
Chemistry (1730) – the art of resolving mixt, compound, or aggregate bodies into their principles; and of composing such bodies from those principles (Stahl).
Chemistry (1837) – the science concerned with the laws and effects of molecular forces (Dumas).
Chemistry (1947) – the science of substances: their structure, their properties, and the reactions that change them into other substances (Pauling).
Chemistry (1998) – the study of matter and the changes it undergoes (Chang).






FORM 4

  1. Element – a substance consists of one type of atom.
  2. Compound – a substance consists two or more elements that are chemically bonded (molecule or ions).
  3. Atomsmallest particle of an element.
  4. Molecule – a group of two or more atoms.
  5. Ion – a positively charged / negatively charged particle.
  6. Isotopes – atoms of the same element with same proton number but different nucleon numbers.
  7. Relative atomic mass of an element = the average mass of one atom of an element/((1/12) x the mass of one carbon-12 atom)
  8. Relative molecular mass of an element = the average mass of one atom of an molecule/((1/12) x the mass of one carbon-12 atom)
  9. Molecule formula – compound shows the actual number of atoms of each element that are present in a molecule of the compound
  10. Empirical formula – compound shows the simplest whole number ratio of atoms of each element in the compound
  11. Mole amount of substance that contains as many particles as the number of atoms in exactly 12 g of carbon-12 the symbol of mole is mol.
  12. One mole – Avogadro constant – 6.02 x 1023
  13. Group (Periodic Table) – vertical columns of element (similar chemical properties).
  14. Periods (Periodic Table) – horizontal rows of element.
  15. Valence electrons – electrons that occupy the outermost shell.
  16. Ionic bond – bond formed through the transfer of electrons between atoms of metal and non-metal to achieve the stable octet electron arrangement.
  17. Ionic compound – consist of positive ions and negative ions which are held by strong electrostatic forces of attraction.
  18. Covalent bond – bond formed through the sharing of non-metal electrons to achieve the stable duplet or octet electron arrangement.
  19. Covalent compound (also simple molecular structure) – consists of neutral molecules which are held by weak intermolecular forces (Van der Waals).
  20. Alkali (base) – chemical substance which ionizes in water to produce hydroxide ions, OH-.
  21. Acid – chemical substance which ionizes in water to produce hydrogen ions, H+ or hydroxonium ions, H3O+.
  22. pH – degree of acidity or alkalinity of a solution. Scale ranges from 0 to 14.
  23. pH value – measure of the concentration of hydrogen ions, H+.
  24. Strong alkali – ionises (dissociates) completely in water to form hydroxide ions, OH- of high concentration.
  25. Weak alkali – ionises (dissociates) partially in water to form hydroxide ions, OH- of low concentration.
  26. Strong acid – ionises (dissociates) completely in water to form hydrogen ions, H+ of high concentration.
  27. Weak acid – ionises (dissociates) partially in water to form hydrogen ions, H+ of low concentration.
  28. Polymer – long chain molecules made up by monomer (repeating unit).
 FORM 5
1. Effective collision (Collision theory) – collision that results in a chemical reaction where the particles collide with the correct orientation and are able to achieve the activation energy.
2. Homologous series – organic compounds (families) with similar formulae and properties.
3. Catalyst – a chemical that alter the rate of reaction.
4. Positive catalyst – increases the rate of reaction & lower the activation energy.
5. Negative catalyst – decreases the rate of reaction & higher the activation energy
6. Organic compounds – carbon-containing compound. Carbon atoms form covalent bonds.
7. Inorganic compounds – compounds from non-living things which do not contain the element carbon.
8. Saturated hydrocarbons – hydrocarbons containing only single bonds between all carbon atoms.
9. Unsaturated hydrocarbons – hydrocarbons containing at least one carbon-carbon double or triple bond.
10. Esterification – esters are produced
11. Vulcanisation – process which makes the natural rubber harder and increases its elasticity by adding sulphur.
12. Redox reaction – chemical reactions involving oxidation and reduction occurring simultaneously.
13. Flavouring – improve the taste or smell of food and restore taste loss due to food processing.
14. Stabilisers – help to mix two liquids that usually do not mix together so that they form an emulsion.
15. Thickeners – substances that thicken food and give the food a firm, smooth and uniform texture.
16. Precipitation – the heat change when one mole of a precipitate is formed from their ions in aqueous solution.
17. Displacement – the heat change when one mole of a metal is displaced from its salt solution by a more electropositive metal.
18. Neutralisation – the heat change when one mole of water is formed from the reaction between an acid and an alkali.
19. Combustion – the heat change when one mole of a substance is completely burnt in oxygen under standard conditions.