C. Distance from Earth
The observed brightness of a star (the apparent magnitude) to an absolute magnitude, you need to know the distance [d], to the star. Alternatively, if we know the distance and the apparent magnitude [m] of a star, we can calculate its absolute magnitude [d].
*paraphrased from "COSMOS.com"
Answer:
I think the answer is C because I know
Answer:
moles = given mass/atomic mass
so H2O mass = 2 +16=18
so 12g of h2o= 12/16 = 3/4 moles
Answer:
2M
Explanation:
M=mol/L
1. Find moles of CoCl2
mass of substance/molar mass = 130/129.833 = 1.001 mol
3. Substitute in molarity equation
M=(1.001/0.5)
M= around 2M
Mass of Oxygen: 0.0159 grams
Moles of Oxygen: 9.94x10^-4
To find the mass of oxygen, subtract the mass of copper from the total mass.

There are 0.0159 grams of Oxygen.
To find how many moles there are, divide the given amount of oxygen by the molar mass (atomic mass) of oxygen because that mass is the same as one mole of oxygen.
Molar mass of Oxygen: 16.00

There are 9.94*10^-4 moles of Oxygen.