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>
Answer
A. molecules
Explanation
When atoms or elements combine, they are called molecules. When molecules combine they form compounds.
The age of the fossil given the present amount of Carbon-14 is given in the equation,
A(t) = A(o)(0.5)^t/h
where A(t) is the current amount, A(o) is the initial amount, t is time and h is the half-life. Substituting the known values to the equation,
A(t) / A(o) = 0.125 = (0.5)^(t/5730)
The value of t from the equation is 17190.
Thus, the age of the fossil is mostly likely to be 17190 years old.
Answer:
Here's what I get
Explanation:
1. Nickel sulfate
base + acid ⟶ salt + water
NiSO₄ is a salt of the base Ni(OH)₂ and the acid sulfuric acid.
Hydroxides of transition metals are insoluble; most sulfates are soluble.
![\underbrace{\hbox{Ni(OH)$_{2}$(s)}}_{\hbox{base}} + \underbrace{\hbox{H$_{2}$SO$_{4}$(aq)}}_{\hbox{acid}} \longrightarrow \, \underbrace{\hbox{NiSO$_{4}$(aq)}}_{\hbox{salt}} + \underbrace{\hbox{2H$_{2}$O(l)}}_{\hbox{water}}](https://tex.z-dn.net/?f=%5Cunderbrace%7B%5Chbox%7BNi%28OH%29%24_%7B2%7D%24%28s%29%7D%7D_%7B%5Chbox%7Bbase%7D%7D%20%2B%20%5Cunderbrace%7B%5Chbox%7BH%24_%7B2%7D%24SO%24_%7B4%7D%24%28aq%29%7D%7D_%7B%5Chbox%7Bacid%7D%7D%20%5Clongrightarrow%20%5C%2C%20%5Cunderbrace%7B%5Chbox%7BNiSO%24_%7B4%7D%24%28aq%29%7D%7D_%7B%5Chbox%7Bsalt%7D%7D%20%2B%20%5Cunderbrace%7B%5Chbox%7B2H%24_%7B2%7D%24O%28l%29%7D%7D_%7B%5Chbox%7Bwater%7D%7D)
2. Carbonate + acid
Most carbonates are insoluble.
They react with acids to form carbonic acid (H₂CO₃), which decomposes into water and carbon dioxide.
![\rm NiCO_{3}(s) + H_{2}SO_{4}(aq) \longrightarrow \, NiSO_{4}(aq) + H_{2}O(l) + CO_{2}(g)](https://tex.z-dn.net/?f=%5Crm%20NiCO_%7B3%7D%28s%29%20%2B%20H_%7B2%7DSO_%7B4%7D%28aq%29%20%5Clongrightarrow%20%5C%2C%20NiSO_%7B4%7D%28aq%29%20%2B%20H_%7B2%7DO%28l%29%20%2B%20CO_%7B2%7D%28g%29)
Answer:
given statement is completely true
e.g . water H2O