The mass of the piece of lead is calculated using the below formula
Q(heat)= mC delta T
Q = 78.0 j
M=mass =?
C=specific heat capacity ( 0.130 j/g/c
delat T=change in temperature = 9.0 c
by making M the subject of the formula
M = Q/ c delta T
M= 78.0 j/ 0.130 j/g/c x 9.0 c = 66.7 g of lead
<span>The word that should be filled in the blank in order to complete the sentence, "The ______ in the mouth secrete enzymes which help prepare the food for digestion in the stomach." The answer would be saliva. Saliva contains salivary amylase that helps soften the food. </span>
Answer:
in the air and soil
in drinking water
on and inside the human body
Explanation: Hope that helps
We can use two equations for this problem.<span>
t1/2 = ln
2 / λ = 0.693 / λ
Where t1/2 is the half-life of the element and λ is
decay constant.
20 days = 0.693 / λ
λ = 0.693 / 20 days
(1)
Nt = Nο eΛ(-λt) (2)
Where Nt is atoms at t time, No is the initial amount of substance, λ is decay constant and t is the time
taken.
t = 40 days</span>
<span>No = 200 g
From (1) and (2),
Nt = 200 g eΛ(-(0.693 / 20 days) 40 days)
<span>Nt = 50.01 g</span></span><span>
</span>Hence, 50.01 grams of isotope will remain after 40 days.
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