<span>i think its Uranium Dating </span>
Answer: higher b. Among compounds of approximately the same molar mass, those with greater polarities tend to have Wiesenthal of vaporization that are (higher, lower.
Explanation: Molecules in a gas are far apart. They are mulct"\ closer together in a liquid. Molecules in a gas are easily squeezed closer together as the gas is compressed and walls more frequently than before and with a greater force per impact.
Answer:
B. - 210 kJ
Explanation:
<em>∵ ΔHrxn = ∑(bond energies)products - ∑(bond energies)reactants.</em>
- The bond formation in the products releases energy (exothermic).
- The bond breaking in the reactants requires energy (endothermic).
The products:
- H₂O contains 2 O-H (- 459 kJ/mol) bonds.
- O₂ contain 1 O=O (- 494 kJ/mol) bond.
The reactants:
- H₂O₂ contain 2 O–H (459 kJ/mol) bonds and 1 O–O (142 kJ/mol) bond.
∵ ΔHrxn = ∑(bond energies)products - ∑(bond energies)reactants.
<em>∴ ΔHrxn = [2 (2 x (O–H bond energy) + (1 x (O=O bond energy)] - 2 [(2 x (O–H bond energy) + (1 x (O–O bond energy)] </em>= [2 (2 x - 459 kJ/mol) + (1 x - 494 kJ/mol)] - 2 [(2 x 459 kJ/mol) + (1 x 142 kJ/mol)] = (- 2330 kJ) + (2120 kJ) = <em>- 210 kJ.</em>
The mass of magnesium in 
atoms is 240 g.
Answer: Option A
<u>Explanation:</u>
First, we have to convert the atoms to moles of magnesium.
We know that atoms are present in 1 mole of magnesium. So,
Thus,
Thus, 240 g of Magnesium is present in atoms.
