B. elements
It's called the periodic table (of the elements)
Answer:
Average atomic mass = 24.3051 amu
Explanation:
Average Atomic Mass = (Mass of Isotope 1 x Fractional Abundance of Isotope 1) + (Mass of Isotope 2 x Fractional Abundance of Isotope 2) + ......
For 24 Mg
Mass = 23.985 amu
Fractional Abundance = 0.7899
Mass * Fractional Abundance = 18.9458
For 25 Mg
Mass = 24.986 amu
Fractional Abundance = 0.10
Mass * Fractional Abundance = 2.4986
For 26 Mg
Mass = 25.983
Fractional Abundance = 0.1101
Mass * Fractional Abundance = 2.8607
Average atomic mass = 24 Mg + 25 Mg + 26 Mg
Average atomic mass = 18.9458 + 2.4986 + 2.8607
Average atomic mass = 24.3051 amu
Answer: There are 
atoms of carbon in the given moles.
Explanation:
We are given 24.6 moles of carbon and we need to find the number of atoms.
According to mole concept:
1 mole of an element contains 
number of atoms.
So, 24.6 moles of carbon will contain 
atoms.
Hence, there are atoms of carbon in the 24.6 moles of carbon.
Answer:
There is 61.538% oxygen in Al2(SO4)3.
Explanation:
Wt Of oxygen in the compound = 12*16 = 192 amu.
Total Wt. Of the compound = 2*12+3*32+12*16 = 312 amu.
Thus, percent of oxygen = Wt of oxygen/total Wt. Of compound *100
= 192/312 * 100=61.538 %
