He proposed the Law of Conservation of Matter, being the first to say that matter can not be created nor destroyed. 
        
                    
             
        
        
        
This answer would be primary consumers
        
                    
             
        
        
        
Answer:
f = 8 Hz
Explanation:
Given data:
Wavelength of wave = 0.5 m
Speed of wave = 4 m/s
Frequency = ?
Solution:
Formula:
f = v/λ
f = frequency
v = speed 
λ = wavelength
Now we will put the values in formula.
f = v/λ
f = 4 m/s / 0.5 m
f = 8 s⁻¹
s⁻¹ = Hz
f = 8 Hz
 
        
             
        
        
        
Answer:
The lowest energy conformer is shown in the figure.
Explanation:
In Cis form both the groups are in the same plane (towards the observer or away i.e on dash line or wedge line)
As shown in the diagram.
For cyclohexane terminology, both should be on up position or down position.  
The two groups should be on equatorial position to have most stable conformation.