Choose the right description ()
An element which obtains an electron possesses positive charge.
B. Silicon might take the place of carbon in forming long chains compounds.
C. Hydrogen is the lightest element.
D. Ozone is a typical nontoxic gas.
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Which reaction can be used to produce electricity ()
A. Double displacement reactions
B. Displacement reactions
C. Redox reactions
D. Combination reactions
Choose the right characterizations of oxygen () ①colourless ②odourless ③tasteless ④Liquid and solid oxygen are pale blue
A. ①②③④
B. ①④
C. ②③④
D. ①③
Which is an excellent insulator even when molten or dissolved in water ()
A. Metallic Crystals
B. Ionic Crystals
C. Molecular Crystals
D. Atomic Crystals
The mathematical treatment of of () is particularly difficult to develop.
A. solid
B. liquid
C. gas
D. molten
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