Ex. 1 Read and translate the text
The properties of metals and nonmetals
Chemists divide chemical elements into metals and nonmetals. All metals have a shiny appearance. They are good conductors of heat and electricity. They form alloys with other metals and have at least one basic oxide. Chemists subdivide metals into several different categories. From left to right in the periodic table, these categories include alkali metals; alkaline earth metals, lanthanides and radioactive actinides; transition metals. Specialized subcategories such as the refractory metals and the noble metals also exist. They are relatively soft. Some metals have a colour (Cu, Cs, Au). Most metals are silvery. They have low densities (e.g. Be, Al) or very high melting points. They are liquids at a room temperature. They are brittle (e.g. Os, Bi).
Nonmetals have open structures. They tend to gain electrons when they react with other substances and do not form basic oxides. Typical nonmetals have a dull, coloured or colourless appearance. They are brittle when they are solid. They are poor conductors of heat and electricity and have acidic oxides. They tend to lose electrons when they react with other substances. They have a high density.
Metalloids tend to share electrons when they react with other substances. They have weakly acidic or amphoteric oxides. Some metalloids conduct electricity. Most of them are gases at room temperature. They have relatively low densities. They are poor electrical and thermal conductors. They have a relatively high ionization energies. They form acidic oxides. People find them naturally in large amounts.
Ex. 2 Answer the questions
How do chemists divide chemical elements?
What do metals form with other metals?
Do nonmetals form basic oxides?
What do nonmetals have?
What appearance do nonmetals have?
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