Answer: B.They are arranged in energy levels
Explanation: Electrons orbit around the nucleus of an atom, and are not spread around equally throughout an atom because there are a different amount of electrons that can fit in each energy level or electron shell (both are the same thing). For example the first energy level can hold up to 2 electrons, the second shell can hold up to 8 electrons, the third can hold up to 18, and so on represented by the equation 2(n^2)
Rust is when a metal turns brown-ish red-ish and that tells you that the metal is old and is no longer useful. we don't want it floating in our bodies because it's rusted metal. hope this helped! :)
Answer:
what are the items that have been listed?
Answer:
a) 0.525 mol
b) 0.525 mol
c) 0.236 mol
Explanation:
The combustion reactions (partial and total) will be:
C₇H₁₆ + (15/2)O₂ → 7CO + 8H₂O
C₇H₁₆ + 11O₂ → 7CO₂ + 8H₂O
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2C₇H₁₆ + (37/2)O₂ → 7CO + 7CO₂ + 16H₂O
It means that the reaction will form 50% of each gas.
a) 0.525 mol of CO
b) 0.525 mol of CO₂
c) The molar mass of heptane is: 7*12 g/mol of C + 16*1 g/mol of H = 100 g/mol
So, the number of moles is the mass divided by the molar mass:
n = 11.5/100 = 0.115 mol
For the stoichiometry:
2 mol of C₇H₁₆ -------------- (37/2) mol of O₂
0.115 mol of C₇H₁₆ --------- x
By a simple direct three rule:
2x = 2.1275
x = 1.064 mol of O₂
Which is the moles of oxygen that reacts, so are leftover:
1.3 - 1.064 = 0.236 mol of O₂
The sample will lose half of its mass after 4 hours. The half life.
82=4
The sample will lose half of the remaining four after another half life.
42=2 Hope this helps! :)
