After 160 years, the activity level of the sample will be 0.5 curies.
<h3>What is half-life?</h3>
Half life of any radioactive waste is the half decay of that product.
The formula is 
Where, λ is 4 cruies
λ1 is 0.5 cruies
b = 40 years
Putting the values in the equation

Thus, the correct option is 160 years.
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Answer:
c
Explanation:
three or more atoms make up one compound
 
        
                    
             
        
        
        
Answer
Rotating 
Explanation:
The Earth is always being pulled towards the Sun by gravity.
The Earth is not moving fast enough to "escape" the Sun's gravity and leave the solar system, but it is going too fast to be pulled into the Sun. Therefore, it keeps going around and around( roating)- orbiting the Sun.
 
        
                    
             
        
        
        
The maximum amount of XeF4 that could be produced is 0.5 moles.
XeF4 = Xe (g) 2 F2 (g) (g)
Xe and F2 have a mole ratio of 1:2. Because of this, the reaction would be limited by F2 when there is 1 mole of Xe and 1 mole of F2.
<h3>What is mole ratio?</h3>
The mole ratio is the ratio of any two compounds' mole amounts that are present in a balanced chemical reaction.
A comparison of the ratios of the molecules required to accomplish the reaction is given by the balancing chemical equation.
A mole ratio is a conversion factor used in chemical reactions to link the mole quantities of any two compounds. A conversion factor's numbers are derived from the balanced chemical equation's coefficients.
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 Answer:
this is fairly simple if you have a periodic table with you.
Explanation:
atomic number 17 is Cl mass numer is 35.45 for protons neutron and electron you can just look that up on google. atomic number is where it is at on the periodic table and the mass number is in the little square at the bottom.