Answer:
169
Explanation:
Mass number is the number of protons and the number of neutrons combined.
70 + 99 = 169
Answer:
hello your question is incomplete attached below is the complete question
Pyridinium ion is more soluble in 0.1 M HCL (aqueous solution) and this is because the Pyridine ion reacts with NaOH and after the reaction it comes out neutral.
N-acetyltyrosine methyl ester is more soluble in 0.1 M HCL while
B-napthol is more soluble in 0.1 M NaOH because it forms phenoxide ion
Explanation:
Pyridine ion is more soluble in 0.1 M HCL (aqueous solution) and this is because the Pyridine ion reacts with NaOH and after the reaction it comes out neutral.
N-acetyltyrosine methyl ester is more soluble in 0.1 M HCL while
B-napthol is more soluble in 0.1 M NaOH because it forms phenoxide ion
attached below is the remaining part of the solution
We are given with the mass of Arsine (
The mass of arsine is 15g
there is a relation between moles, mass and molar mass of any compound which is

The molar mass of Arsine = atomic mass of As + 3X atomic mass of H
the molar mass of Arsine = 74.92 + 3X 1 = 77.92 g/mol
Let us calculate the moles as

A) Selenium - is apart of Sulfur family