<u>Given:</u>
Initial amount of carbon, A₀ = 16 g
Decay model = 16exp(-0.000121t)
t = 90769076 years
<u>To determine:</u>
the amount of C-14 after 90769076 years
<u>Explanation:</u>
The radioactive decay model can be expressed as:
A = A₀exp(-kt)
where A = concentration of the radioactive species after time t
A₀ = initial concentration
k = decay constant
Based on the given data :
A = 16 * exp(-0.000121*90769076) = 16(0) = 0
Ans: Based on the decay model there will be no C-14 left after 90769076 years
The answer is D . I hope this help you :) .
Answer:
-5.51 kJ/mol
Explanation:
Step 1: Calculate the heat required to heat the water.
We use the following expression.

where,
- c: specific heat capacity
- m: mass
- ΔT: change in the temperature
The average density of water is 1 g/mL, so 75.0 mL ≅ 75.0 g.

Step 2: Calculate the heat released by the methane
According to the law of conservation of energy, the sum of the heat released by the combustion of methane (Qc) and the heat absorbed by the water (Qw) is zero
Qc + Qw = 0
Qc = -Qw = -22.0 kJ
Step 3: Calculate the molar heat of combustion of methane.
The molar mass of methane is 16.04 g/mol. We use this data to find the molar heat of combustion of methane, considering that 22.0 kJ are released by the combustion of 64.00 g of methane.

O2 is an element As it contains just one kind of atom, O2 is an element,
Answer: Avogrado's Constant
Explanation:
One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant. The concept of the mole can be used to convert between mass and number of particles.