Answer:
Check explanation
Explanation:
Gold - Au (Aurum)
Mercury - Hg (Hydrargyrum) 
Copper - Cu (Cuprum) 
Iron - Fe (Ferrum)
Lead - Pb (Plumbum)
These elements in the periodic table are some of the elements represented by letters not in line with their names.
This is because, these elements were known in ancient times and therefore, they are represented by letters from their ancient names.
 
        
             
        
        
        
I think it is because the electrons repel each other
        
             
        
        
        
Answer:
The required new pressure is 775 mm hg.
Explanation:
We are given that gas has a volume of 185 ml and a pressure of 310 mm hg. The desired volume is 74.0 ml.
We have to find the required new pressure.
Let the required new pressure be ' '.
'.
As we know that Boyle's law formula states that;
                     
where,  = original pressure of gas in the container = 310 mm hg
 = original pressure of gas in the container = 310 mm hg
             = required new pressure
 = required new pressure 
              = volume of gas in the container = 185 ml
 = volume of gas in the container = 185 ml
              = desired new volume of the gas = 74 ml
 = desired new volume of the gas = 74 ml 
So,   
   
         
 
             =  775 mm hg
Hence, the required new pressure is 775 mm hg.
 
        
             
        
        
        
Answer: 
the density of mobile electrons in the material is 3.4716 × 10²⁵ m⁻³
Explanation:
 Given the data in the question;
we make use of the following expression;
hall Voltage VH = IB / ned
where I = 2.25 A
B = 0.685 T 
d =  0.107 mm =  0.107 × 10⁻³ m
e = 1.602×10⁻¹⁹ C
VH = 2.59 mV = 2.59 × 10⁻³ volt
n is the electron density
so from the form; VH = IB / ned
VHned = IB
n = IB / VHed
so we substitute
n = (2.25 × 0.685) / ( 2.59 × 10⁻³ × 1.602×10⁻¹⁹ × 0.107 × 10⁻³ )
n = 1.54125 /  4.4396226 × 10⁻²⁶ 
n = 3.4716 × 10²⁵ m⁻³
Therefore, the density of mobile electrons in the material is 3.4716 × 10²⁵ m⁻³
 
        
             
        
        
        
Answer:
34.5 m
Explanation:
Given data : An elephant produces 10 Hz sound wave. Assuming the speed of sound in air is 345 m/s. To find : What is the wavelength of sound ? Answer : The wavelength of the sound is 34.5 m.