Answer:
116 years
Explanation:
To solve this, we will use the half life equation;
A(t) = A_o(½)^(t/t_½)
Where;
A(t) is the amount of strontium left after t years;
A_o is the initial quantity of strontium that will undergo decay;
t_½ is the half-life of strontium
t is the time it will take to decay
We are given;
A(t) = 7.5 g
A_o = 120 g
From online values, half life of strontium-90 is 29 years. Thus, t_½ = 29
Thus;
7.5 = 120 × ½^(t/29)
Divide both sides by 120 to get;
7.5/120 = ½^(t/29)
0.0625 = ½^(t/29)
In 0.0625 = (t/29) In ½
-2.772589 = (t/29) × (-0.693147)
(t/29) = -2.772589/(-0.693147)
t/29 = 4
t = 29 × 4
t = 116 years
Answer:
Explanation:
Researchers hope to gain knowledge about how the microbiome contributes to health and disease states.
The average atomic mass of oxygen is the atomic mass with respect to 1/12th the mass of a C-12 atom, related to natural abundance.
amu - atomic mass units
O-16 - 15.995 amu
O-17 - 16.999 amu
O-18 - 17.999 amu
the average atomic mass is 15.9994 amu
average atomic mass = ∑atomic mass of each isotope * relative abundance percentage
in other words the average atomic mass is closer to the atomic mass of the most abundant isotope. In this case 15.9994 is closest to 15.995 amu which is the atomic mass of O-16.
This means that O-16 is the most abundant isotope.
Answer:
Glucose is a primary source of energy for living organisms. Animals transport glucose and oxygen to tiny structures in their cells, called mitochondria.
Hope this helps ;-))
Answer:
The oceans are the very foundation of human life. life itself arose from the oceans. The oceans are vast, covering about 140 million square miles, some covering 72 percent of the earth's surface.
Explanation:
