Atomic number of C is 6. Hence, there are 6 electrons in carbon.
The electronic configuration of carbon is 1s2, 2s2, 2p2
Here, there are 2 unpaired electron. However, C2+ ions have 2 electrons less as compared to C.
Hence, electronic configuration of C 2+ ion is 1s2, 2s2. All the electrons are paired in this system. So there are no unpaired electrons in C 2+ ion.
The correct answer is B. Chewing in the mouth breaks food into small pieces.
Explanation:
In physical changes, substances do not change their chemical composition or properties but only physical features such as this. This occurs during the chewing because the action of chewing only makes food to be broken down in smaller pieces but does not change its identity, composition, or properties. This does not occur once the food is in contact with saliva, the acid in the stomach, etc. because in these cases, the food reacts with other substances and a chemical reaction occurs, which changes food's identity and composition.
Moles of nitrogen = 49.84 / 28 = 1.78
Moles of hydrogen = 10.7 / 2 = 5.35
Molar ratio of nitrogen to hydrogen = 1 : 3
Hydrogen required = 1.78 x 3 = 5.34
Therefore, hydrogen is in excess and nitrogen is the limiting reagent.
Reference table J?
In general though reactions happen when one element wants to replace another element in another molecule/compound. So in this case you are essentially looking for the most reactive metal of the 4 choices. Elements become more reactive as you go down the periodic table, and metals become more reactive as you move left along the period, meaning Alkali metals are the most reactive metals, and Francium is the most reactive metal.
Based on this knowledge we can assume that Potassium is the most reactive of the choices and thus most readily reacts with HCl to produce H2 gas. And if you want prood check out this video!
https://www.youtube.com/watch?v=53T5WZHQ_Ck
