PV=nRT
P= ? atm
V= 2 L
T= 423 K
n= 2.3 moles
R= 0.08205
(P)(2)=(2.3)(0.08205)(423)
P= (79.826445)/(2)
P= 39.9132225 atm
The answer is "A. a pure substance can be separated by chemical means, while a mixture can be separated by physical means". A pure substance only has one type of substance, whereas a mixture has more than one. A pure substance therefore, can only be separated chemically, because it is not two things mixed together, whereas a mixture can be separated physically because there are multiple substances.
Answer: 
Explanation: Because barium is in Group 2, it forms ions with a charge of +2. Fluorine, in Group 17, form ions with a charge of -1. Cross the charges to get the subscripts (Since Ba has a charge of +2, F has a subscript of 2. Because F has a charge of -1, Ba needs a subscript of 1). Therefore, a formula unit of the compound is .
Answer:
scientific investigation is the quest to find an answer to a question using scientific method.
Explanation:
Answer: The law of conservation of mass is reffering to the fact that energy cannot be created or destroyed. So when you speak about atoms not being created or destroyed it is the same thing. Unless you're talking about an atomic bomb where the atoms are split.
