Our main source of energy is the sun. True.
Tropic levels have most energy
Answer:
Pb₂O₄
Explanation:
The given species are:
Pb⁴⁺ O²⁻
Now, to solve this problem, we use the combining powers which corresponds to the number of electrons usually lost or gained or shared by atoms during the course of a chemical combination.
Pb⁴⁺ O²⁻
Combining power 4 2
Exchange of valencies 2 4
Now the molecular formula is Pb₂O₄
Answer:
Moles of Hydrogen produced is 5 moles
Explanation:
The balanced Chemical equation for reaction between zinc and sulfuric acid is :

This equation tells that ; when 1 mole of Zn react with 1 mole of sulfuric acid, it produces 1 mole of zinc sulfate and 1 mole of hydrogen.
Since sulfuric acid is in excess so Zinc is the limiting reagent
(Limiting reagent : Substance which get consumed when the reaction completes, limiting reagent helps in predicting the amount of products formed)
Limiting reagent (Zn) will decide the amount of Hydrogen produced


So,

Hence moles of Hydrogen produced is 5 moles
Answer: Option (a) is the correct answer.
Explanation:
Ionic salts are defined as the salts which tend to contain ionic bonds as there occurs transfer of electrons between its combining atoms.
So, when an ionic salt melts or it is dissolved in water then it will dissociate into its respective ions and as electricity is the flow of electrons or ions. Hence, this salt is then able to conduct electricity.
As covalent compounds are insoluble in water so, they do no dissociate into ions. Hence, they do not conduct electricity.
Similarly, metallic and network solids do not dissociate into ions either when melted or dissolved in water. Therefore, they also do not conduct electricity.
Thus, we can conclude that when a white crystalline salt conducts electricity when it is melted and when it dissolves in water then this bond is of ionic type.