When bonds are formed, energy is released. in a water molecule, the two hydrogens are both bonded by single bonds to the central oxygen atom. the bond energy associated with an o–h bond is 463 kj/mol. again, using the balanced chemical equation shown above, how much energy is released in forming the o–h bonds?

The balanced chemical equation is:

2H2 + O2 → 2H2O

Based on the reaction stoichiometry:

2 moles of water are formed.

Each water molecule has 2 O-H. Thus, a total of 4 O-H bonds are formed.

Energy released/O-H bond = 463 kJ/mol

For 4 O-H bonds this would be= 4 * 463 = 1852 kJ

Ans: Thus, -1852 kJ (negative sign indicates that energy is released) in the forming of O-H bonds.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them