Answer:
A. 32.6 g/mol
Explanation:
First convert the volume of gas to moles using the ratio 1 mol / 22.4 L at STP.
0.070 L • (1 mol / 22.4 L) = 0.00313 mol
Now divide the grams of gas by the moles of gas:
0.102 g / 0.00313 mol = 32.6 g/mol
The average atomic mass of the imaginary element : 47.255 amu
<h3>Further explanation </h3>
The elements in nature have several types of isotopes
Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
Mass atom X = mass isotope 1 . % + mass isotope 2.% ..
isotope E-47 47.011 amu, 87.34%
isotope E-48 48.008 amu, 6.895
isotope E-49 50.009 amu, 5.77%
The average atomic mass :

Answer:
Propane
Explanation:
From the question given, we were told that 0.1240 kg of propane reacted with excess oxygen to produce 0.3110kg of carbon dioxide.
Since the reaction took place in the presence of excess oxygen, therefore, propane is the limiting reactant as all of it is used up in the presence of excess oxygen.
Answer:
electron cloud charge of manganese=-5
Explanation:
atomic number=number of elecron +neutron number
DATA
Neutron NO.=30
atomic NO.=25
e=?
A=e+n
25=e+30
e=25-30
e= -5
B is true if we subtract atomic number(the number of protons )from the mass number
we can find neutrons.
hope this helps