The mass number is the summation of number of proton and neutron present in a nucleus of an atom. For the neutral atom the number of positive charge (number of proton) must be equal to the number of electrons. The number of electrons present in an atom is the atomic number of the atom. The standard way to express the mass number (a) and atomic number (m) of a atom (say X) is 
. Now for silicon number of electron or atomic number is 14. And the mass number (a) given 29. Thus the expression nucleus of silicon will be 
"(2) increase in suburbanization" was a direct result of the <span>baby boom that followed World War II, but of course there were other factors that resulted as well. </span>
Answer:
moles of CO2 can be produced from a reaction of 10.0 moles C2H6
Explanation:
In this reaction -
2 moles of C₂H6 produces four molecules of Carbon dioxide (CO2)
So 1 mole of C₂H6 will produce 
moles of Carbon dioxide (CO2)
Thus, 10 moles of C₂H6 will produce 
moles of Carbon dioxide (CO2)
Assuming the question is asking for percent composition by mass,
The molar mass of sodium bicarbonate is:
22.990 + 1.008 + 12.011 + 3*15.999 = 84.006 g/mol
The molar mass of 3 oxygen atoms is:
3*15.999 = 47.997 g/mol
The percentage composition by mass is:
47.997/84.006 * 100% = 57.1% (3 s.f.)
Answer:
The element is Dysprosium.
