Chemical Hazards

Сабақтың жоспары

План урока

2. Жана материалды мазмұндау (баяндау)/ Изложение нового материала

Read the text CHEMICAL HAZARDS and guess Kazakh equivalent for the terms:

vapor - пар, бу, dust - пыль, шаң, fume - дым, түтін, mist - туман, тұман, fiber – волокно, талшық

CHEMICAL HAZARDS

These are commonly classified as either particulate or gas and vapor contaminants. The most common particulate contaminants include dusts, fumes, mists, aerosols, and fibers. Dusts are solid particles that are formed or generated from solid organic or inorganic materials by reducing their size through mechanical processes such as crushing, grinding, drilling, abrading or blasting.

Fumes are formed when material from a volatilized solid condenses in cool air. In most cases, the solid particles resulting from the condensation react with air to form an oxide.

Fibers are solid particles whose length is several times greater than their diameter. The term mist is applied to a finely divided liquid suspended in the atmosphere. Mists are generated by liquids condensing from a vapor back to a liquid or by breaking up a liquid into a dispersed state such as by splashing, foaming or atomizing. Aerosols are also a form of a mist characterized by highly respirable, minute liquid particles.

Gases are formless fluids that expand to occupy the space or enclosure in which they are confined. Examples are welding gases such as acetylene, nitrogen, helium, and argon; and carbon monoxide generated from the operation of internal combustion engines or by its use as a reducing gas in a heat treating operation. Another example is hydrogen sulfide which is formed wherever there is decomposition of materials containing sulfur under reducing conditions.

Liquids change into vapors and mix with the surrounding atmosphere through evaporation. Vapors are the volatile form of substances that are normally in a solid or liquid state at room temperature and pressure. They are formed by evaporation from a liquid or solid and can be found where parts cleaning and painting takes place and where solvents are used.

The degree of worker risk from exposure to any given substance depends on the nature and potency of the toxic effects and the magnitude and duration of exposure.

3. Рефлексия бақылау блогы/ Рефлексивно – оценочный блок

Білімдерін бекіту/ Закрепление знаний

Antonyms: 1-m, 2-k, 3-p, 4-o, 5-i, 6-n, 7-l, 8-j, 9-e, 10-h, 11-b, 12-g, 13-a, 14-f, 15-d, 16-c

Synonyms: 1-l, 2-f, 3-k, 4-h, 5-j, 6-b, 7-i, 8-d, 9-g, 10-e, 11-c, 12-a

Рефлексия

1. Which type of Hazards is described in the text?

2. What are the types of Chemical hazards?

Үй тапсырмасы – to know basic words, retelling

қолы ___________________