Answer: B
. particle size
Explanation:
Let's begin by explaining that a molecular sieve is a device, whose composition allows the absorbtion of molecules that are small enough to pass through its pores, since it is made up of small pores of a precise and uniform size.
Thus, very small molecules manage to pass through the pores of the sieve, while large ones do not.
So, based on this premise, a molecular sieve separates the substances by their size.
Hence, the correct option is B.
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:
Warm air rises, resulting in a decrease air pressure.
Explanation:
Tornado is the rapid and violent rotation of column of air which move from the thunderstorm to the ground.
It is formed when there is collision between warm and cold air. The cold air which is more sense than the warm air is pushed over the warm air which result in thunderstorms. The warm air then rises which result in decrease air pressure causing an updraft. The updraft then begin to rotate as there are variations in wind speeds and directions.
Answer:
a mole have have wrong becouse i understand