<h2>Answer:</h2>
The mass of the system will remain the same if there is no conversion of mass to energy in the reaction.
<h3>Explanation:</h3>
- If the system is closed, then according to the law of mass conservation the mass of the reaction system will remain the same.
- <u><em>Law of conservation of the mass: In simple words, it is described as the mass of a closed system can never be changed, it may transfer from one form to another or change into energy.</em></u>
- But if the reaction involves energy transfer like heat or light production, in this case, the mass can be changed.
As you proceed down the periodic table, the metallic character becomes stronger. This is because as the atomic radius increases, there is less attraction between the nucleus and the valence electrons due to the greater distance between them, making electrons simpler to shed.
Answer:
Electrolysis (of hydrochloric acid) is a way of splitting up (decomposition) of the compound (hydrogen chloride in water) using electrical energy.
Explanation:
The electrical energy comes from a d.c. (direct current) battery or power pack supply. A conducting liquid, containing ions, called the electrolyte (hydrochloric acid), must contain the compound (hydrogen chloride) that is being broken down.
Answer:
3.43 %
Explanation:
We need to calculate first the number of moles of CeO2 produced in the combustion. Given its formula we know how many moles of Ce atom are present. From there calculate the mass this number of moles this represent and then one can calculate the percentage.
0.1848 g CeO2 x 1 mol CeO2/172.114g = 0.00107 mol CeO2
0.00107 mol CeO2 x 1 mol Ce/ 1 mol CeO2 = 0.00107 mol Ce
.00107 mol Ce x 140.116 g Ce/ mol = 0.150 g Ce
0.150 g Ce/ 4.3718 g sample x 100 = 3.43 %
Answer:
About 60.
Explanation:
Mendeleev knew of 63 elements. He wrote their properties on cards and arranged them in order of atomic mass.
That's how he discovered that the properties of elements are periodic functions of their atomic masses.
