Titlebook: Mastering Chemistry; P. Critchlow Textbook 1982Latest edition Macmillan Publishers Limited 1982 chemistry

错

Macmillan Publishers Limited 1982

规范就好

恩惠

Very First PrinciplesA rod of plastic, a pen for example, that has been rubbed with cloth attracts small pieces of paper or hair. The pen has been ‘charged with electricity’. Two pens ‘charged’ in this way will repel one another, as the experiment in Fig. 1.1 shows. The same results are obtained when two glass rods are used in place of the two plastic pens.

Evocative

预兆好

Energy Changes in ChemistryA small lump of potassium, when dropped into water, rushes about on the surface as a molten ball of metal, sparking, bursting into flame, hissing and heating up the water as it goes.

facilitate

容易做

Ions and ElectricityAny small electrically charged particle is called an .. Section 3.3(f) showed how elements to the left of the Periodic Table, the metals, tend to form positive ions by losing electrons. Non-metals (found to the right of the Table) can form negative ions by electron gain.

纹章

AcidsTo many people, chemistry is to do with acids, and acids are dangerous corrosive liquids.

吸引人的花招

The MetalsThe . that we shall consider are shown in . in Table 11.1.

certitude

The Non-MetalsThe non-metals are found to the right of the Periodic Table, as shown in Table 12.1. They bond covalently with each other, usually to form individual small molecules: for example as diatomic molecules . or polyatomic molecules ..