To determine the moles in 40 grams of magnesium, we need the atomic weight. This can easily be found on a periodic table. For this problem, let's use 24.305 grams/mole.
We are going to set up an equation to determine this problem. In this equation, we want all our units to cancel out except for 'moles.'

In this, we can see that the unit 'grams' will cancel out to leave us with moles.
In solving the equation, we determine that there are approximately 1.65 moles of Magnesium.
Answer:
phosphorus.
Explanation:
The atomic number of phosphorus is 15 so the protons will be 15.
Lord dragon you are wrong.
The answer is A: Incandescent light bulbs are almost 100 percent efficient. Because b-d do not make any sense.
Answer: Because water has a high specific heat capacity due to the hydrogen bonding within the H₂O molecules ; so it takes a great deal of energy, or heat, to break these bonds— or to form them.
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5mg in liter is 5 ppm
Explanation: 1 ppm is one part per million.
1 ppm is 1 mg is one part of million from 1 kg = 1000 000 mg
1 litre water is 1. Kg.