Answer:
147.2g
Explanation:
The full solution can be found in the image attached. Graham's law was applied to the problem. The rate of diffusion of a gas is inversely proportional to its molar mass or vapour density. Molar mass= 2vapour density
 
        
             
        
        
        
Answer:
1. Alkali metals (group 1)
2. halogens (Group 17)
3. noble gasses (group 18)
Explanation:
1. alkali metals only have one valence electron meaning that they really want to lose that one valence electron to get a full octet.
2. halogens have 7 valence electrons meaning that they just need to gain 1 to get a full octet.
3. Nobel gasses already have a full octet meaning that they don't want to react. (atoms only react to get a full octet)
I hope this helps.  Let me know if anything is unclear.
 
        
             
        
        
        
H2SO4 or hydrogen sulfate is an acid and NaOH or sodium hydroxide is a base or an alkali. The reaction between an acid and a base or alkali produces a salt and water. The reaction between these substances is shown below:
H2SO4 (aq) + 2NaOH (aq)------>2H20 (L) + Na2SO4 (aq). The salt produced in this reaction is sodium sulfate. 
        
                    
             
        
        
        
Answer: Contamination
Explanation: This is a known contrainst when performing transformation in the lab. Normally the Pglo plasmid asides glowing under UV, possess a Amp gene that codes for resistance to the antibiotics Ampicillin. Transform cells will survive while untransformed cells will normally die. If untransformed (non glowing, non Ampicillin resistant) cells thrive in the medium, it is definitely a case of contamination. Start again but this time, disinfect appropriately bad be cautious of any potential contamination.