1. False, the water being stored behind the dam has potential energy until it begins to flow through the dam (it is then converted to kinetic energy).
2. True
3. True
Hope this helped! :)
Answer:
option A is correct ( sodium, calcium and barium)
Explanation:
Given compounds:
Sodium chloride , calcium sulfide, barium oxide
We know that metals form positive ions. In order to solve the problem we must identify the metals from given compounds.
Na⁺Cl⁻
Ca²⁺S²⁻
Ba²⁺O²⁻
We can see that sodium, calcium and barium contain positive charges.
Thus option A is correct.
Because sodium have one valance electron. When it combine with chlorine sodium lose its one electron to complete the octet and chlorine accept it to complete its octet. Thus sodium form positive ion and chlorine form negative ion.
Similarly barium and calcium are present in group 2. Both have two valance electron. When they lose them cation are formed.
Other option are incorrect because,
Option B have sulfur and oxygen which are anion.
Option C have chlorine which is also anion
Option D have chlorine, sulfur and oxygen that are anions.
It has to do with the releasing of ethylene, which speeds up the ripening process
The best explanation would be A. The reason the balloon is inflated is because its filled with gas, and the gas particles collide with the interior of the balloon to give it its shape.
It is B, smoke and air pollution can stress the lungs and cause things like Respiratory distress if not wearing a proper mask. That is why in places with massive amounts of air pollution many people will wear face masks.
