Answer:
A- A demonstration shows how something works, often including models
Explanation:
A demonstration allows, through experimentation, to show how nature works and in that way can include the explanation of scientific theories that explain the set of observed facts, that is, it serves as a demonstration of the underlying scientific principles.
Answer: The chemical formula for the compound of these two elements is 
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here metal lead is having an oxidation state of +4 called as
cation and sulphur non metal has oxidation state of -2 called as
. Thus they combine and their oxidation states are exchanged and written in simplest whole number ratios to give neutral 
The chemical formula for the compound of these two elements is 
Answer:
emf induced in the loop, at the instant when 9.0s have passed = 1.576 * 10 ⁻² V.
Direction is counter clockwise.
Explanation:
See attached pictures.
i thinkits an instrument called seismograph. not sure
Unlike charges attracting each other