Why does ionization energy increase across a period

 effective nuclear charge increases as electron shielding remains constant. ... The increased distance weakens the nuclear attraction to the outer-most electron, and is easier to remove (requires less energy).

Explanation:

In general, ionization energy increases across a period and decreases down a group. Across a period, effective nuclear charge increases as electron shielding remains constant. ... The increased distance weakens the nuclear attraction to the outer-most electron, and is easier to remove (requires less energy).

electrons

Explanation:

more electrons hold the valence electrons more tightly to the nucleus

valence electrons are the electrons on the outer most ring in the electron cloud

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.

because natural gas is colorless, odorless, and tasteless, distributors add mercaptan (a chemical that smells like sulfur) to give natural gas a distinct unpleasant odor (it smells like rotten eggs). they locate the types of rock that are likely to contain natural gas deposits.