Answer:
3 bonds are needed.
Explanation:
The electrons that are involved in chemical bonding are those in the outer shell of the highest energy level of the atom. The electron configuration of nitrogen (N) is 1s²2s²2p³. That means thy at each nitrogen atom has 5 valence electrons: 2 electrons in the 2s orbital and 3 electrons in the 2p orbital. To fullfil the octet, each nitrogen atom needs 3 electrons. So, they can share each other 3 electrons to form 3 simple bonds. Therefore, the nitrogen molecule (N₂) has 3 bonds involving 6 bonding electrons or a triple bond.
The full question asks to decide whether the gas was a specific gas. That part is missing in your question. You need to decide whether the gas in the flask is pure helium.
To decide it you can find the molar mass of the gas in the flask, using the ideal gas equation pV = nRT, and then compare with the molar mass of the He.
From pV = nRT you can find n, after that using the mass of gass in the flask you use MM = mass/moles.
1) From pV = nRT, n = pV / RT
Data:
V = 118 ml = 0.118 liter
R = 0.082 atm*liter/mol*K
p = 768 torr * 1 atm / 760 torr = 1.0105 atm
T = 35 + 273.15 = 308.15 K
n = 1.015 atm * 0.118 liter / [ 0.082 atm*liter/K*mol * 308.15K] =0.00472 mol
mass of gas = mass of the fask with the gas - mass of the flasl evacuated = 97.171 g - 97.129 g = 0.042
=> MM = mass/n = 0.042 / 0.00472 = 8.90 g/mol
Now from a periodic table or a table you get that the molar mass of He is 4g/mol
So the numbers say that this gas is not pure helium , because its molar mass is more than double of the molar mass of helium gas.
<span>The calculation of quantities in chemical equations are called Stoichiometry. Stoichiometry is a branch of chemistry which deals with relative quantities of reactants and products in chemical reactions. The correct answer is 'Stoichoimetry'. I hope this helps you. </span>
Answer: A
Explanation: The spindle fibers bring the chromosomes together in prophase then apart in telophase.
B.
Explanation:
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