КОНТРОЛЬНЫЕ МАТЕРИАЛЫ I. Образцы текстов по специальности для чтения и перевода
1.Примерный текст для чтения и обсуждения в 3-ем семестре для продолжающих/ 4-м семестре для начинающих на 2-м курсе
Fundamental concepts of chemistry
Adapted from: The World Book Encyclopedia. Volume 3. 1992. Chicago: World Book Inc, 1992, pp. 366-7.
1. Read the text and fill in the gaps with the following expressions in appropriate forms. Use each expression only once.
chemical formula, chemical equation, proton, neutron, element, electron, atomic nucleus, molecule, cation, anion, chemical compound, chemical reaction, chemical bonds, ion, molecule, atomic number An atom is a collection of matter consisting of a positively charged core (the ________________) which contains ____________ and ____________ and which maintains a number of electrons to balance the positive charge in the nucleus. The atom is also the smallest portion into which an ____________ can be divided and still retain its properties, made up of a dense, positively charged nucleus surrounded by a system of ____________.
The most basic chemical substances are the chemical elements. They are building blocks of all other substances. An element is a class of atoms which have the same number of protons in the nucleus. This number is known as the ___________ ____________of the element. For example, all atoms with 6 protons in their nuclei are atoms of the chemical element carbon, and all atoms with 92 protons in their nuclei are atoms of the element uranium. Each chemical element is made up of only one kind of atom. The atoms of one element differ from those of all other elements. Chemists use letters of the alphabet as symbols for the elements. In total, 117 elements have been observed as of 2007, of which 94 occur naturally on Earth. Others have been produced artificially.
An ____________ is an atom or a molecule that has lost or gained one or more electrons.
Positively charged ____________ (e.g. sodium cation Na+) and negatively charged ___________(e.g. chloride Cl−) can form neutral salts (e.g. sodium chloride NaCl).