In general chemistry, isotopes are a group of substances that belong to the same element. An element is characterized in the periodic table by their atomic number, which is the number of protons in an atom. Therefore, these substances have the same atomic numbers, but differ in mass numbers. Mass number is the sum of the number of protons and neutrons in the nucleus of an atom.
To determine the atomic weight of an element, you take the average weight of all the existent isotopes of that said element. The calculation would require to multiply the exact mass of the isotope to its abundance. Then, sum them all up.
Atomic weight = 98(0.18) + 112(0.82)
Atomic weight = 109.48 amu
You have already gotten the balanced equation. And the ratio of mol number of reactants and production is the ratio of coefficient. So there is 6.4/8*11=8.8 mol oxygen needed. The mass is 8.8*32=281.6 g.
The answer is A . Saturated solution
One is closer to the equator so be must be warmer
Answer: The amount of heat needed is = 4.3kJ
Explanation:
Amount of heat H = M × C × ΔT
M= mass of benzene = 64.7g
C= specific heat capacity = 1.74J/gK
ΔT = T2-T1
Where T1 is initai temperature = 41.9C
T2 is the final temperature( boiling point of benzene) = 80.1C
H= 64.7×1.74×80.7
H= 4300J
H=4.3kJ
Therefore, the amount of heat needed is 4.3kJ