Task 5
What do trace elements serve as?
Do we definitely know the exact role of trace elements?
What is another name of vitamin B12?
What does a deficiency of cobalt result in?
What is copper associated with?
How does the utilization of glucose take place?
What is an important source of fluoride?
Where is the biggest source of iodine contained?
Where is manganese contained?
What does zinс deficiency lead to?
Task 5
What did the ancient people always want to discover?
Whose ideas have radically changed?
How many kinds of atom does an element consist of?
How are elements characterized by ?
How are compounds produced?
What aren’t substances changed in?
How may oxygen and hydrogen be mixed?
Why is oxygen the most important element to man?
How much of the Earth’s crust do oxygen,silicon,aluminium and hydrogen constitute ?
Where Have astronomers found common elements?