How many valence electrons are in c4h6br2?

Based on octet rule, elements would fill up their outermost shell with 8 electrons to be stable. In this case, Carbon has 4 valence on its outer shell, Hydrogen has only 1 valence, while Bromine has 7. Therefore the total valence electrons are:

total valence = 4*4 + 1*6 + 7*2 = 16 + 6 + 14

total valence = 36

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.

clouds form

solid ice forms on leaves.

water droplets form on grass.