Answer: A different group of scientists using different methods.
 
        
             
        
        
        
What is the correct name for the cyclic alkane shown on the right? 1,3-dimethyl, 3-ethylcyclohexane 1-ethyl, 1,4-dimethylcyclohexane 1-ethyl-1,3-dimethylcyclohexane 1-ethyl-1,3-dimethylcyclopentane 1,3 dimethyl, 3- ethylcyclopentane A
        
             
        
        
        
Answer:
25%
Explanation:
Half life means that 50% of the sample is gone at 3.3 years. This means that an additional 3.3 years (total 6.6 years) will reduce the sample a further 50% from the point at 3.3 years. In numbers, this means 50% of 50% (0.50*0.50), which is 25%.
 
        
             
        
        
        
Explanation:
To answer this question, we'll need to use the Ideal Gas Law:
p
V
=
n
R
T
 ,
where 
p
 is pressure, 
V
 is volume, 
n
 is the number of moles 
R
 is the gas constant, and 
T
 is temperature in Kelvin.
The question already gives us the values for 
p
 and 
T
 , because helium is at STP. This means that temperature is 
273.15 K
 and pressure is 
1 atm
 .
We also already know the gas constant. In our case, we'll use the value of 
0.08206 L atm/K mol
 since these units fit the units of our given values the best.
We can find the value for 
n
 by dividing the mass of helium gas by its molar mass:
n
=
number of moles
=
mass of sample
molar mass
 
=
6.00 g
4.00 g/mol
=
1.50 mol
 
Now, we can just plug all of these values in and solve for 
V
 :
p
V
=
n
R
T
 
V
=
n
R
T
p
=
1.50 mol
×
0.08206 L atm/K mol
×
273.15 K
1 atm
= 33.6 L
this is not the answer but it will help you
do by the formula it is on the answer
 
        
             
        
        
        
Answer:
The highest sea-level pressure on Earth occurs in Siberia
Explanation:
 where the Siberian High often attains a sea-level pressure above 1050 mbar (105 kPa; 31 inHg), with record highs close to 1085 mbar (108.5 kPa; 32.0 inHg).