The answer is D I hope this helps you !
Answer: It is called a Crookes Tube, and he used it to discover cathode rays, which were later determined to be electrons.
I assume this is a true or false question. I would say true
The major groups of minerals includes: carbonate ions and oxides, . In addition to this three groups the following are also the major groups of minerals
native elements
sulfate
sulfides
halides
silicate
nitrate among others such as phosphate and vanadate
The balanced chemical equation for the above reaction is as follows;
2Ca + O₂ --> 2CaO
stoichiometry of Ca to O₂ is 2:1
this means that 2 mol of Ca reacts with 1 mol of O₂.
If O₂ is the limiting reactant,
4 mol of O₂ should react with (4x2) - 8 mol of Ca
however only 7.43 mol of Ca is present. Therefore Ca is the limiting reactant.
7.43 mol of Ca reacts with - 7.43/2 = 3.715 mol of O₂
therefore there's excess O₂₂ remaining after the reaction
Since Ca is the limiting reactant, it is fully used up in the reaction and there is no Ca remaining after the reaction is completed.