The element with 4 protons in the nucleus in Beryllium.
Answer:
Charge the balloon, hold it near an electroscope, and determine if the electroscope leaves move.
Explanation:
The gold leaf electroscope is an instrument used to detect if a body is charged. It has two gold leafs suspended from a brass stem in a vacuumed glass jar and connected to a metal cap(Toppr).
When the test body is allowed to touch the metal cap, a change in the size of the leaves shows whether the body is charged or not.
Since we are suspecting the balloon to be made up of a metal; metals can be charged. We can test if there is really a charge on the balloon by bringing it near an electroscope to see if the electroscope moves.
Answer:
A. 3 x 10-12
Explanation:
Generally, the parts-per notation is used to represent very small concentration without any specific unit.
Parts per million is notated as 
Parts per billion is notated as 
Parts per trillion is notated as 
Hence, 3 parts per trillion will be written as 3 x 
The correct option is A.