Magnesium oxide is 60.3% magnesium by mass. What is the mass fraction of magnesium in magnesium oxide? a. 0.603
b. 0.397
c. 39.7
d. 60.3
e. None of these

A. 0.603

Explanation:

Mass fraction of an element in a substance = mass of that element / total mass of the substance.

Mass of magnesium = 24.3g/mol

Mass of oxygen = 16g/mol

Total mass of MgO = 24.3+16 = 40.3g/mol

Hence, the mass fraction of magnesium in Magnesium oxide =

24.3/40.3

= 0.6029

= 0.603

Another way is to divide the percentage by mass of magnesium by 100 i.e. 60.3% = 60.3/100

= 0.603

the tides are influenced by both the moon and the sun, it's easy to see that when the sun lines up with the moon and the earth, as during a new moon or full moon, the tidal effect is increased. these are known as spring tides, named not for the season, but for the fact that the water "springs" higher than normal. on the other hand, if the sun and the moon are 90 degrees apart in relation to an observer on earth as during the first quarter moon or third quarter moon, then high tides are not as high as they normally would be. this is because despite its greater distance, the sun's mass allows it to exert enough gravitational force on the oceans that it can negate some of the effects of the moon's pull. this phenomenon of lower high tides is called a neap tide. if you need more information on this topic visit moonconnection.com.