I would say
D. Gravity pulled particles of dust and gas together to form planets.Hope it helped!
Answer:
Sodium peroxide can be prepared on a large scale by the reaction of metallicsodium with oxygen at 130–200 °C, a process that generates sodium oxide, which in a separate stage absorbs oxygen: 4 Na + O2 → 2 Na2O. The ozone oxidizes the sodium to form sodium peroxide.
Answer:1. ![Rate=k[CHCl_3]^1[Cl_2]^\frac{1}{2}](https://tex.z-dn.net/?f=Rate%3Dk%5BCHCl_3%5D%5E1%5BCl_2%5D%5E%5Cfrac%7B1%7D%7B2%7D)
2. The rate constant (k) for the reaction is 
Explanation:
Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.
![rate=k[CHCl_3]^x[Cl_2]^y](https://tex.z-dn.net/?f=rate%3Dk%5BCHCl_3%5D%5Ex%5BCl_2%5D%5Ey)
k= rate constant
x = order with respect to 
y = order with respect to 
n = x+y= Total order
1. a) From trial 1:
(1)
From trial 2:
(2)
Dividing 2 by 1 :![\frac{0.0069}{0.035}=\frac{k[0.020]^x[0.010]^y}{k[0.010]^x[0.010]^y}](https://tex.z-dn.net/?f=%5Cfrac%7B0.0069%7D%7B0.035%7D%3D%5Cfrac%7Bk%5B0.020%5D%5Ex%5B0.010%5D%5Ey%7D%7Bk%5B0.010%5D%5Ex%5B0.010%5D%5Ey%7D)
therefore x=1.
b) From trial 2:
(3)
From trial 3:
(4)
Dividing 4 by 3:
therefore 
![rate=k[CHCl_3]^1[Cl_2]^\frac{1}{2}](https://tex.z-dn.net/?f=rate%3Dk%5BCHCl_3%5D%5E1%5BCl_2%5D%5E%5Cfrac%7B1%7D%7B2%7D)
2. to find rate constant using trial 1:

Answer: 2.26x 10²⁴ atoms C
Explanation: To get the number of atoms,
First we convert mass of C to moles
45g C x 1mole C / 12 g C
= 3.75 moles C
Cancel g of C
Next convert moles of C to atoms using Avogadro's Number.
3.75 moles C x 6.022x10²³ atoms C / 1 mole C
Cancel out the units of moles C.
= 2.26x 10²⁴ atoms of C