I think it’s the circulatory system. it delivers oxygen and nutrients to the cells and pumps blood to the heart. hope this helps:)
Answer:
2.99×10²⁵ molecules of CO₂ are produced
Explanation:
Decomposition reaction is:
Ca(HCO₃)₂ => CaO(s) + 2CO₂(g) + H₂O(g)
Ratio is 1:2. Let's make a rule of three:
1 mol of bicarbonate can produce 2 moles of CO₂
Therefore, 24.9 moles of bicarbonate may produce, 49.8 moles (24.9 .2 )/1
Let's determine the number of molecules
1 mol has 6.02×10²³ molecules
49.8 moles must have (49.8 . 6.02×10²³) / 1 = 2.99×10²⁵ molecules
Answer:

Explanation:
Hello!
In this case, since the reaction between phosphorous and oxygen to form diphosphorous pentoxide is:

Thus, since phosphorous is in excess and oxygen and diphosphorous pentoxide are in a 5/2:1 mole ratio, we can compute the maximum moles of product as shown below:

Best regards!
When, it donates electons.
as for example take
NaCl ( sodium chloride)
it's an ionic compund,
that means it is formed by donating or gaining electrons
Na is writen first than, it must be electropositive i.e it has donated electons which made it positive and the clorine gains electron so it's electronegative.
Na is positive because
as we know it's atomic number is 11 that means it has 11 protons and 11 electrons
now, when it donate electon it has, greater number of protons whose change is +ve so the atom becomes overall positively charged ion or cation.
and something same happens in clorine and because it gains one electron and the number of electrons increase in it by 1 whise charge is -ve so, the atom becomes negatively charged ion or anion which has a -1 charge.