CHAPTER 9 Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII MATERIAL CONVERSION  Physical conversion Physical conversion is a conversion that does not produce new material and temporal only.  Chemical conversion Chemical conversion is a conversion that produces new material and goes permanently, not returning to original material. New material is the material that its properties are different from its original material and can not change to its original property. Material conversion Physical conversion Chemical conversion

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII PERUBAHAN FISIKA & KIMIA  PERBEDAAN PERUBAHAN FISIKA DAN KIMIA Physical conversionChemical conversion  Not forming any new substance  Reversible  No chemical reaction  Forming some new substances  Irreversible  There is a chemical reaction, it is proven by the formation of gas, precipation, colour, and energy conversion.

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII PHYSICAL CONVERSION  PHYSICAL CONVERSION IN OUR DAILY LIFE 1.Physical conversion caused by form change ConversionExample MeltingThe melting of Candle, iron, and aluminum. Evaporation The evaporation of sea-water, ether, and eucalyptus oil. LiquationThe liquation of ice, and snow. DewingAqueous vapor dews FreezingThe freezing of water, oil, and gel. SublimatingDry ice becomes gas, solid menthol sublimates becoming steam, and camphor sublimates.

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII PHYSICAL CONVERSION 2.Physical conversion caused by resolvability Sugar property that is melted in the water like sweetness still can appear If the solution evaporates. There will be both the same sugar and taste. The process of making syrup, acetate, and alcohol of 70 % are the kinds of physical conversion. 3.Physical conversion caused by the form change The material conversion and wood becomes a chair is the kind of physical conversion. It is because the wood only change in its shape, but the property does not change. The chair property is same with wood. It is the same case in the change of raw wood becomes wood pieces, bamboo becomes angklung, paper becomes paper-toys, and cloth becomes clothes.

Electindo.com FISIKA SMP KELAS VII PHYSICAL CONVERSION 4.Physical conversion caused by energy current for bulb, the wolfram wire does not change. The bulb only converts the electric energy to the light energy, The electric bell coil only converts the electric energy to moving energy so that it makes a voice. The element of electrical iron only converts electric energy to heat energy. So, it is a physical conversion because in this case the material only acts as energy current conductor.

Electindo.com FISIKA SMP KELAS VII CHEMICAL CONVERSION  CHEMICAL CONVERSION IN DAILY LIFE 1.Physical conversion caused by burning burning is a chemical reaction between the burned material and oxygen. The process of burning caused by fire, burning does not only produce ash and gas, but also energy. Example, the candle burning produces light energy, and the gasoline or diesel oil burning produces moving energy. In our daily life, there are so many burning chemical reactions, such as burning wood, paper, candle, gasoline, or diesel fuel, or bomb explosion.

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII CHEMICAL CONVERSION 2.Chemical conversion caused by decomposition Decomposition is the chemical reaction caused by micro- organism. For food, it gets odor, rotten, and coming out gas. For instance, rotten rice or moldy bread. The both decomposed foods can not be as their first form. 3.Chemical conversion caused by fermentation Fermentation is a kind of chemical conversion because the fermented food will be softer, more aromatic, and taste differently. E.g. in the process of making sticky-tapai and cassava-tapai. The sticky-tapai is made of sticky-rice, while the cassava-tapai made of cassava. By fermentation, sticky- rice and cassava become tapai. Tapai has different characteristic from its ingredients. Moreover, it can be turned neither to be sticky-rice nor cassava.

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII CHEMICAL CONVERSION 4.physical conversion caused by heating The solution of salt that is heated will produce salt. That is why the salt solution considered as a physical conversion. And cooking rice is a kind of chemical conversion. It is because the hulled-rice becoming cooked-rice. The cooked- rice can not be turned to be hulled-rice anymore. Like the other processes, the heating process like poaching corn and cassava, frying egg, or making soft-cake, those foods become softer so that easy to be digested.

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII CHEMICAL CONVERSION 5.Chemical conversion caused by photosynthetic Photosynthetic is a reaction of constructing a compound that occurs at greenery. Photosynthetic process is a chemical conversion because the greenery processes water and carbon dioxide by the help of sun so that it can produce carbohydrate and oxygen. 6.Chemical conversion caused by corrosion Corrosion is a chemical reaction between iron, oxygen, and water. This reaction produces corrosion that is generally metal oxide. Corrosion is a chemical conversion because it does not produce a new substance.

Electindo.com PHYSICS FOR JUNIOR HIGH SCHOOL VII THANK YOU