Answer: 
Explanation: 1 gram is equal to 1000 Milligrams so

Since you go straight across its just multiplication so 0.00200x1000=200mg
To answer it in scientific notation it should just be
mg
Answer:
i think C the higher the frequency the lower the energy of light.
It’s A
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Formation reaction is the formation of 1 mole of product from the constituents of the reactant molecules. The mass of oxygen that must react is 182 gm.
<h3>What is mass and molar mass?</h3>
Mass of the substance is the weight while the molar mass of the substance is the addition of the atomic mass of the individual mass of the constituent atoms of the compound or the molecule.
The chemical reaction can be shown as:

From the reaction, it can be said that 3 moles of oxygen are required to produce 2 moles of aluminium oxide, so x moles of oxygen will be required to produce 3.80 moles of aluminium oxide.
Solving for x:

If 1 mol of oxygen is 32 gm then 5.7 moles of oxygen will be 182.4 gm.
Therefore, option D. 182 gm is the mass of oxygen required.
Learn more about moles and molar mass here:
brainly.com/question/893495