Using 3 – 4 sentences explain (in your own words) why water expands when it freezes?

In the case of water, that is, when the liquid water gets cooled, it gets contract to a temperature of about 4 degrees is attained. However, after that, it starts to expand somewhat till it moves towards the freezing point, and eventually when it freezes, it expands by about 9 percent.  

This characteristic has its source in the composition of the water molecule. In water, there possesses a capacity to produce a network of hydrogen bonds, where each atom of hydrogen is in a line amongst the two atoms of oxygen. This tendency of hydrogen bonding gets robust as the temperature lowers down. The formed ice structure is completely hydrogen-bonded and these bonds permit the structure to get open, thus, expansion takes place.  

the equation that correctly represent the reaction for formation of ammonia is

n2+ 3h2 → 2nh3 (answer d)

1 mole of nitrogen gas (n2) react with 3 moles of hydrogen gas (h2) to form 2 moles of ammonia ( nh3). this is in a process known as haber process were iron is used as a catalyst and reaction take place that a higher temperature and pressure. the process is exothermic hence energy is released.

2b2t

explanation:

2b2t