Answer : The correct options are,
and 
Explanation :
Single displacement reaction : It is a type of chemical reaction in which the more reactive element displaces the less reactive element.
Option A reaction : 
It is an example of double displacement reaction because in this reaction a positive cation and a negative anion of the two reactants exchange their places to form two new products.
Option B reaction : 
It is an example of single displacement reaction.
Option C reaction : 
It is an example of combination reaction because in this reaction two reactants react to give a single product.
Option D reaction : 
It is an example of decomposition reaction because in this reaction a single reactant decomposes into two or more products.
Option E reaction : 
It is an example of single displacement reaction because in this reaction the most react element, aluminium displaces the less reactive element, hydrogen.
Hence, the options B and E are single displacement reactions.
Answer:
The particles that compose a gas are so small compared to the distances between them that the volume of the individual particles can be assumed to be negligible.
Explanation:
This is a postulate of the Kinetic Molecular Theory.
A is wrong. KMT assumes the that the volume of the particles is negligible.
B is wrong. KMT assumes that the distance between the particles is muck greater than their size.
D is wrong. It takes the large distances as a fact. KMT uses this as an assumption.
Answer:
19.9 atoms
Explanation:
Grams --- Moles --- Atoms
You're converting from atoms (molecules) to moles.
You do not have to calculate the mass of "di phosphorus pentoxide."
Since you're already given 1.2x10^25 atoms, you start with that. You need to cancel out the atoms, so you need Avogadro's number as shown in the image.
(This has nothing to do with the problem) But in case if you're wondering, the "di" in phosphorus means there's 2 phosphorus and the "pent" means that there are 5 oxygens. So P2O5. Go to your periodic table, multiply their respective atomic masses. You would multiply phosphorus twice and oxygen 5 times. And add them up to get the overall mass.
I hope this helped!
Answer: The answer is D) The entire table of data provides evidence that as the corn percentage increases in the feed, the weight gain in pigs also increases.
Explanation: