Gr.7 Chemistry Ch 9 Quiz-2

2. The use of ________________ in chemistry saved chemists time.

 

• symbols

• signs

• symptoms

2. The use of ________________ in chemistry saved chemists time.

 

• symbols

• signs

• symptoms

3. Most substances are made from two or more elements that are joined together,

    They are called ________________.

 

• atoms

• elements

• compounds

5. Compound of some elements are used to make ______________

• Firework

• food

• camp fire

6. Sodium and chlorine form a __________________ compound.

• sodium chlorite

• Sodium chloride

• sodium chlorate

7. A process in which one substance spreads out trhough another.

• diffusion

• dissolve

• mixing

8. At the top of very high mountains the atmospheric pressure is less than at sea level.

• True

• False

9. The first twenty elements of the periodic table begins with hydrogen

    and ends with ___________________.

• magnesium

• sodium

• calcium

10. The first chemists were called _________________.

• alchemists

• pharmacists

• pathologists

1.In 1813 _____________________ introduced the symbols to represent the

     elements

• Einstien 

• Jon JaKob Berzellius

• H Davy