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.
Answer:
it causes alot of harm to the earth.
Explanation:
earthquakes
an so on
Answer:
The half life is 
Explanation:
The half life of a first order reaction is mathematically represented as
Substituting
for the rate constant

30% should be the percentage of oxygen if the total mass of fe2o3 is 160.