In 1996, astronomers discovered an icy object beyond pluto that was given the designation 1996 tl 66. it has a semimajor axis of 84 au. what is its orbital period according to kepler’s third law?

772.65 years.  

Explanation:

Semi major axis = R = 84 AU = 1.257 × 10¹³ m

According to the 3rd law of Kepler, T² =  4 π² R³ / GM

Here R is the semi major axis. G = 6.67 × 10⁻¹¹ SI units.

M is the mass of the  Sun  = 1.98 x 10³⁰ kg

T² =    4 (3.14)³ (1.257 × 10¹³ )³÷ (6.67 × 10⁻¹¹)(1.98 x 10³⁰)

  ⇒  Time period  =  T = 2.44 x 10¹⁰ seconds

1 s = 3.17 × 10⁻⁸ years

Converting the seconds to years, T = 772.65 years.

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂

i don't understand. explain it clearly