Revesion




1) Put ( right ) & ( wrong ) in front of these statement and correct the wrong one : -



1- Carbon is found in petroleum oil , saccharides and chiorophyll.




2- The chemical formula for Epsom salt is magnesium sulphate.




3- the elements exist in the same period have similar properties.




4- silver bromide is used in cooking utensils industry.




5- chlorine gas can undergoes sublimation process.






Write one importance for each of the following:-



1- Metalloids…………………………………………………………………………………………………………



2- Gieger counter …………………………………………………………………………………………..



Give reasons for :-



1- Semi-metallic elements are called semi-conductors.



2-Elements in group ( 1a ) are not founding elementary state.



3-Chlorine cl17 is monovalent , while magnesium Mg12 is divalent.


Mr.mohamed abo-mosalam

جزاك الله خيراً