The activity of the sample when it was shipped from the manufacturer is 4.54 mCi
<h3>How to determine the number of half-lives that has elapsed </h3>
From the question given above, the following data were obtained:
- Time (t) = 48 hours
- Half-life (t½) = 14.28 days = 14.28 × 24 = 342.72 hours
- Number of half-lives (n) =?
n = t / t½
n = 48 / 342.72
n = 0.14
<h3>How to determine the activity of the sample during shipping </h3>
- Number of half-lives (n) = 0.14
- Original activity (N₀) = 5.0 mCi
- Activity remaining (N) =?
N = N₀ / 2ⁿ
N = 5 / 2^0.14
N = 4.54 mCi
Thus, the activity of the sample during shipping is 4.54 mCi
Learn more about half life:
brainly.com/question/2674699
Answer:
Grass, deer, wolf, fungi.
Explanation:
The tropical level of an organism is defined as the position of organism occupied in the food chain. The food chain is starts from tropical level one which is primary producers (such as plants), then move to herbivores (such as deer) in level two, carnivores, (such as wolf) at level three, apex predators in level four (such as lions), and it ends in decomposers such as fungi.
Fungi play important role in ecosystem to help in breakdown of dead organic matter and return nutrients to the soil. Without fungi nutrients cannot cycle in an ecosystem, and causing the breakdown of entire food web.
Answer: The moles of melatonin are 0.000043
Explanation:
According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number of particles.
To calculate the moles, we use the equation:
Given mass of melatonin = 0.01 g
Molar mass of melatonin = 232.28 g/mol
Thus the moles of melatonin in 0.01 g are 0.000043
The number of moles of a gas if it occupy a volume of 4dm at 10 atm and - 200 c is 6.67 moles
calculation
by use of ideal gas equation
that is PV =nRT
where P(pressure) = 10 atm
V( volume) = 4dm^3 = 4L
n(number of moles) =?
R(gas constant) = 0.0821 L.atm/mol.K
T = -200 +273 = 73 K
make n the formula of the subject n = PV/RT
n is therefore = (10 atm x 4l)/(0.0821 L.atm/mol.K x 73 K) = 6.67 moles
Answer:
Scientists have figured out that several genes are involved in skin color.
Explanation:
Parents can have children with skin color that is significantly lighter or darker than their own. Sometimes a particular gene can have a much bigger effect than other genes.