Chemical changes<span> occur when a substance combines with another to form a new substance, called </span>chemical<span> synthesis or, alternatively, </span>chemical <span>decomposition into two or more different substances.
So which one do you think is the answer?</span>
2Ca + O2 = 2CaO
First, determine which is the excess reactant
72.5 g Ca (1 mol) =1.8089725036
(40.078 g)
65 g O2 (1 mol) =2.0313769611
(15.999g × 2)
Since the ratio of to O2 is 2:1 in the balanced reaction, divide Ca's molar mass by 2 to get 0.9044862518. this isn't necessary because Ca is already obviously the limiting reactant. therefore, O2 is the excess reactant.
Now do the stoichiometry
72.5 g Ca (1 mol Ca) (1 mol O2)
(40.078 g Ca)(2 mol Ca)(31.998g O2)
=0.0282669621 g of O2 left over
Answer:
1.Molecules are made of atoms. So different molecules can have different (or same) number of atoms they are made of.Different atoms are made of different number of protons of neutrons in the nucleus (also electrons around the nucleus but they are very small even compared to atom and don’t add up for volume or mass) therefore their radius and mass are different.
2.Chromatography works because of differences in the properties of molecules in materials.some molecules differ in shape and size. These differences in molecular properties allow scientists to separate compounds into individual molecules using chromatography.
Explanation:
hope this helps
Tinnitus is the ringing in ears or buzzing and hissing
