Answer:
220.42098 amu
Explanation:
(220 .9 X  .7422) + (220 X .0.1278) + (218.1 X 0.13) =     220.42098 amu
These are weighted averages. 
 So, we will take mass of one and multiply by abundance percentage that is provided and add them together.
In order to calculate the  average atomic mass, we have to convert the percentages of abundance to decimals. So, you get
(220 .9 X  .7422) + (220 X .0.1278) + (218.1 X 0.13) =     220.42098 amu
 
        
             
        
        
        
Oxidation number of an atom is the charge that atom would have if the compound is composed of ions. In neutral substances that contains atoms of one element the oxidation number of an atom is zero. Thus atoms in O2, Ni2, and aluminium all have oxidation number of zero.
In this case, Ni2, the oxidation number of Ni atom is zero, 
for NiO4-, assuming oxidation number of Ni is x 
 (x ×1) + (-2 × 4) = -1
  x = + 7
Therefore, the oxidation number goes from 0 to +7
        
             
        
        
        
Answer: Yes, light can bend around corners. In fact, light always bends around corners to some extent.
Explanation:This is a basic property of light and all other waves. ... The ability of light to bend around corners is also known as "diffraction".
 
        
                    
             
        
        
        
All of the the answers are are correct but a fume hood is more for if you are dealing with chemicals that can produce fumes the are deadly to people
        
             
        
        
        
The typically bald, rocky, or sandy surfaces in desert climates hold little moisture and evaporate the little rainfall they receive.