Explain mendeleev's law about the mendeleev table.

In 1869, Mendeleev came up with the a law that describe the pattern of elements:“when the elements are arranged in order of increasing atomic mass, certain sets of properties recur periodically."

Mendeleev’s law describes the pattern of element in Mendeleev’s table.

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.