chemistry experiments for children

(lily) #1

This is the same as saying: 4(H's)+2(0's)~4(H's)+2(0's). In regular
language, theequationnow says: when four atoms of hydrogen unite with two
atoms of oxygen, two molecules of water result. Thinkaboutthis for a while
and see if you can explain how and why theequationis now balanced.
As you begin to do your experiments, try to get into the habit of using
symbols, formulas and equations. But never let incorrect ones stay uncorrected.
Itwould be misleading to you and to anyone who might read your notebook.
An incorrect equation is even worsethana misspelled word.
, Youhave undoubtedly noticedthatthe' symbols for someofthe elements are
the same as the first letter or first two letters of the element. Others, such as
Na for sodium, are not the same at all. The reason isthatthe symbols are based
on the Latin (or Latinized) names for the elements. In many cases itjusthappens
thatthe first letters of the Latin and English names for an element are the same.
Here are some of the most common elements with symbols unlike their first
letters:
Element Latin Name Symbol
copper cuprum Cu
gold aurum Au
iron ferrum Fe
lead plumbum Pb
mercury hydrargyrum Hg
potassium kalium K
silver argentum Ag
sodium natrium Na
There are also certain clues tounderstandingthe verbal language of chemis-
try. Obviously, when you see the names of certain elements or roots of the
names in a compound, you can tellthatthose elements are contained in the
compound. Thus if you see the phrase "sodiumchloride," you knowthatit
refers to acompoundcontaining the elements sodium and chlorine. There are
also a number of common prefixes and suffixes used in the language of
chemistry that tell youaboutthe composition of acompound.Thesuffix"ide,"
for example, means simply "in combinationwith." Sodium chloride then is
simply sodium in combination with chlorine. The suffix "ate," however,
indicates the presence of oxygen as well. Thus "potassiumchlorate" must
consist not only of potassium and chlorine, but also of oxygen.
Certain atoms group together very tightly in a unit known as aradical,which
you will learn moreabouton page 69. For now, all you need to know isthat
some of the most common radicals are the sulfate radical•.consisting of sulfur
and oxygen; thenitrateradical, consistingofnitrogen and oxygen; and the

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