Elements, Mixtures and Compounds Essay Example | Topics and Well Written Essays - 1000 words

Elements, Mixtures and Compounds - Essay Example For example, a mixture of iron and sulfur can be taken in any proportion while a compound such as iron (II) sulfide always has a ratio of 7 : 4 by mass of iron and sulfur (Leong & Aik, 2009). When a mixture is prepared by mixing two or more substances, there is no chemical exchange involved and there is absence of heat or light production. When a compound is prepared, it is usually accompanied with a chemical change in which some heat, light or both are liberated. For example, when a mixture is prepared by mixing iron filings and sulfur, no heat is liberated. However, when hot iron filings and sulfur are taken together in a test tube, a chemical reaction occurs resulting in the formation of iron sulfide (Fe + S ?FeS). The test tube glows red because of heat produced during the reaction (Leong & Aik, 2009). The properties of a mixture are characteristic of the individual substances mixed. On the contrary, the properties of a compound are very different from those of the original eleme nts. For example, in a mixture of iron filings and sulfur, properties such as magnetism, color, texture of the individual substances are retained. Iron sulfide, a compound, has very different properties from those of iron and sulfur. It lacks magnetic activity and also has different physical and chemical properties (Leong & Aik, 2009). ... 2) Supposed that you have a pure substance, how can you tell whether it is a compound or an element?   An element cannot be further broken down chemically, while a compound can be broken down into individual components or elements using chemical reactions specific for that compound. For example, heating mercuric oxide, which is a compound, over a Bunsen flame, will result in the decomposition and separation of mercuric oxide into mercury and oxygen. However, mercury and oxygen, which are elements, cannot be further broken down using any chemical means (Leong & Aik, 2009). Therefore, in order to tell whether a given pure compound is an element or a compound, it will be subjected to various separation procedures to determine if it can be broken down further. Its melting and boiling points and other physical and chemical properties will also be noted and compared with those of preexisting elements and compounds for ease of identification. 3) What is the difference between an ionic and a covalent bond? Chemical bonds such as ionic and covalent bonds determine the properties of a compound. The main differences between the two kinds of bonds are discussed as follows: Ionic bond is formed when electrons are transferred from one atom to another. The transfer of electrons results in the formation of a positive and a negative ion that are held together by strong electrostatic attraction. For example, salt (NaCl) is formed when an electron from sodium (Na) is transferred to chlorine (Cl) to form ions (Na+ and Cl- ) that are held together to form salt (NaCl). Covalent bond is formed when an electron pair from the outer shell is shared between two atoms. For instance, Hydrochloric acid

Renoirs adaptation of maupassants A counrty excursion Essay

Renoirs adaptation of maupassants A counrty excursion - Essay Example In the context of French cinema, works of such iconic writers as Victor Hugo, Emile Zola and Alexander Dumas were heavily drawn upon. Guy de Maupassant’s short story A Country Excursion is one among many instances of early cinema embracing literature. But there are numerous challenges in adapting a work of art to a radically different medium. Theatre and cinema can be said to share some affinity in terms of principles of mise-en-scene, accepted rules of screen-play, shared exploration of genres, etc. But literature to film is a big leap and film theorist Dudley Andrew identifies three basic types of adaptation – borrowing, intersecting and transforming sources. In the case of A Day in the Country to varying degrees all the three types are at play. Borrowing: The film is said to be borrowed from the short story to the extent that there is divergence in their details pertaining to characterization, geographic description, projection of individual motive, etc. In borrowing , â€Å"the artist employs, more or less extensively, the material, idea, or form of an earlier, generally successful text...the adaptation hopes to win an audience by the prestige of its borrowed title or subject...at the same time it seeks to gain a certain respectability, if not aesthetic value, as a dividend in the transaction†. (Andrew, p.422) Renoir’s work satisfies some of these criteria better than others. Certainly the literary work is the very basis for the project of the film. Moreover, Maupassant was a household name in early twentieth century France, and thus brings a degree of prestige to the project at hand. But the particular short story, A Country Excursion, does not have the same name recollection as its author does. Renoir’s enterprise does succeed in fulfill the twin key criteria of bringing respectability and aesthetic value to the transaction. The cinema produced is no injustice to the artistic standards of its source. The additional provis ions afforded by the new medium add more vibrancy and color to the source text. So the idea of the film can certainly be said to have been borrowed, though with certain qualifications. Intersection: This form of adaptation is found to be the weakest in A Day in the Country. Intersection is the most infidel methods of transmuting words to film due to its limited objective. The goal of the filmmaker is less constrained, for he/she is not concerned with the entire written work but only one idea/feature within it. The task then is to experiment and find out what ‘cinema’ as a medium can ‘do’ to the original. At its heart is creative curiosity and experimentation on the part of the director. Renowned French film critic Andre Bazin has expressed intersection through the metaphor of light. Andrews paraphrases Bazin thus, â€Å"here the original artwork can be likened to a crystal chandelier whose formal beauty is a product of its intricate but fully artificial ar rangement of parts while the cinema would be a crude flashlight intersecting not for its own shape or the quality of its light but for what it makes appear in this or that dark corner† (Andrews, p.423) Seen in light of this definition, A Day in the Country is the cinematic intersection of the literary work, for it brings to the table unique cinematic qualities of expression. This is most evident in passages in the film where dialogue takes