As you go across a period, radius shrinks because you are adding protons. The added positive charge increases pull on the electron shells.
As you go down a group, radius gets larger because you are increasing shells of electrons. This increases shielding of the nucleus' positive charge, so the electrons are not pulled in as much.
Answer:15 +18
Explanation:15 fuel +18 oxygen + 33 cd
Answer:
1.608
Explanation:
According to Graham's effusion law, the rate of effusion (r) of a gas in inversely proportional to the root square of its molar mass (M). The ratio rNH₃ to rCO₂ is:

If CO₂ and NH₃ are allowed to effuse through a porous membrane under identical conditions, the rate of effusion for NH₃ will be 1.608 times that of CO₂.