Webb has calculated the percent composition of a compound. How can he check his result? A) by making sure they are in the lowest ratio
B) by adding them to see if they total 100
C) by checking that they are whole-number multiples
D) by dividing them by the molar mass

by making sure they are in the lowest ratio. by adding them to see if they total 100. by checking that they are whole-number multiples. by dividing them by the molar mass.

indium, and thallium have three electrons i think

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8