No. on the left side you will notice there is one Ca, and 2 oxygen. therefore on the right side there must be 1 Ca, and 2 oxygen. The correct answer would be Ca + O2 -> CaO2
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.
<span>
</span>
Calcium forms an ionic bond to iodine and forms calcium iodide (CaI2). The calcium atom gives away 2 of its valence electrons, one to each of the 2 iodine atoms thus forming the ionic bond.
<span>Cu + 2 AgNO</span>₃<span> = 2 Ag + Cu(NO</span>₃<span>)</span>₂
mole ratio:
1 mole Cu --------------> 2 moles Ag
? mole Cu --------------> 3.50 moles Ag
moles Cu = 3.50 x 1 / 2
moles Cu = 3.50 / 2
= 1.75 moles
Answer B
hope this helps!