Page 71 - SCERT Kerala State Syllabus 8th Standard Basic Science Textbooks English Medium Part 1_Neat

Compounds are pure substances formed from two or more
elements through chemical combination. Compounds can be
converted into its constituent elements through suitable
chemical processes. Find more examples for compounds and
note them in the science diary.
• Water • Sugar

• •
Elements are pure substances which cannot be split into simpler
components through chemical processes. Compounds are substances
Berzelius formed by the combination of two or more elements through chemical
reactions.
In early days, pictures
were used as the symbols Origin of the names of elements
of elements. The modern
Have you ever thought how each element got its name?
method of assigning
symbols was developed In the past, the elements were named after places, countries,
by the Swedish scientist continents, characteristic properties, scientists, planets, satellites
Berzelius. etc.
Berzelius also discovered Note some of the examples given below.
the elements Selenium,
Element The basis of naming
Thorium, Cerium and
Silicon. Polonium Poland - Country
Curium Marie Curie - Scientist
Chromium Chrome - Colour
Indium Indigo - Colour

Chlorine Chloro - Colour
Neptunium Neptune - Planet
Europium Europe - Continent
Berzelius
Table 5.1
(1779 - 1848) Find the basis for giving names to the elements in the Table
given below, and complete the table.
Element The basis of naming

Americium ......................................................................
Francium ......................................................................
Rubedium ......................................................................
See kalziumold in Plutonium ......................................................................
IT @ School Edubuntu,
for finding out how Titanium ......................................................................
elements got their Mendelevium ......................................................................
names.
Rutherfordium ......................................................................
Table 5.2
Basic Science VIII
70 70 Basic Science VIII