When energy transforms into mass, the amount of energy does not remain the same. When mass transforms into energy, the amount of energy also does not remain the same. However, the amount of matter and energy remains the same. ... You would weigh much less on the Moon because it is only about one-sixth the mass of Earth. So the answer is D
Answer:
5.0 x 10⁹ years.
Explanation:
- It is known that the decay of a radioactive isotope isotope obeys first order kinetics.
- Half-life time is the time needed for the reactants to be in its half concentration.
- If reactant has initial concentration [A₀], after half-life time its concentration will be ([A₀]/2).
- Also, it is clear that in first order decay the half-life time is independent of the initial concentration.
- The half-life of K-40 = 1.251 × 10⁹ years.
- For, first order reactions:
<em>k = ln(2)/(t1/2) = 0.693/(t1/2).</em>
Where, k is the rate constant of the reaction.
t1/2 is the half-life of the reaction.
∴ k =0.693/(t1/2) = 0.693/(1.251 × 10⁹ years) = 5.54 x 10⁻¹⁰ year⁻¹.
- Also, we have the integral law of first order reaction:
<em>kt = ln([A₀]/[A]),</em>
where, k is the rate constant of the reaction (k = 5.54 x 10⁻¹⁰ year⁻¹).
t is the time of the reaction (t = ??? year).
[A₀] is the initial concentration of (K-40) ([A₀] = 100%).
[A] is the remaining concentration of (K-40) ([A] = 6.25%).
∴ (5.54 x 10⁻¹⁰ year⁻¹)(t) = ln((100%)/( 6.25%))
∴ (5.54 x 10⁻¹⁰ year⁻¹)(t) = 2.77.
∴ t = 2.77/(5.54 x 10⁻¹⁰ year⁻¹) = 5.0 x 10⁹ years.
Answer:
A) dietary fiber isn't used by the body.
Explanation:
The food we eat contains certain nutritional contents that provides energy, measured in calories (CAL) to the body. A procedure called BOMB CALORIMETRY can be used to determine the energy contents of these foods. The energy-supplying macromolecules contained in food substances we eat are carbohydrate, protein, fats etc.
Bomb calorimetry uses the method of burning the food substance in a device called bomb calorimeter, and measure the caloric content of the burnt food. Bomb calorimetry measures all the present calories in a food substance, which can include dietary fibers. Due to this reason, it is considered a poor choice in determining the number of nutritional calories in a food substance.
Dietary fibers are indigestible carbohydrates that cannot be broken down and used by the body. They pass along the alimentary canal until they are egested. Hence, they are no source of nutrients to the body. Since bomb calorimetry measures all calories including dietary fibers, it is said to overestimate the caloric content of food substances.
Answer:
The answer to your question is T = 7.25 °K
Explanation:
Data
Temperature = ?
moles = 0.80
volume = 275 ml
pressure = 175 kPa
constant of ideal gases = 0.082 atm l/ mol °K
Process
1.- Use the ideal gas law to solve this problem
PV = nRT
-Solve for Temperature
T = PV / nR
2.- Convert Pressure to atm
1 atm --------------- 101.325 kPa
x --------------- 175 kPa
x = (175 x 1) / 101.325
x = 1.73 atm
3.- Convert volume to liters
1000 ml ---------------- 1 l
275 ml ----------------- x
x = (275 x 1) / 1000
x = 0.275 l
4.- Find the temperature
T = (0.275 x 1.73) / (0.8 x 0.082)
-Simplification
T = 0.476 / 0.0656
-Result
T = 7.25 °K
Answer:
8.1 × 10² g
Explanation:
Step 1: Write the balanced equation
2 C₅₇H₁₁₀O₆ + 163 O₂ ⇒ 114 CO₂ + 110 H₂O
Step 2: Convert 1.6 lb of C₅₇H₁₁₀O₆ to g
We will use the conversion factor 1 lb = 453.592 g.
1.6 lb × 453.592 g/1 lb = 7.3 × 10² g
Step 3: Calculate the moles corresponding to 7.3 × 10² g of C₅₇H₁₁₀O₆
The molar mass of C₅₇H₁₁₀O₆ is 890.83 g/mol.
7.3 × 10² g × 1 mol/890.83 g = 0.82 mol
Step 4: Calculate the moles of water produced from 0.82 moles of C₅₇H₁₁₀O₆
The molar ratio of C₅₇H₁₁₀O₆ to H₂O is 2:110. The moles of H₂O produced are 110/2 × 0.82 mol = 45 mol
Step 5: Calculate the mass corresponding to 45 moles of H₂O
The molar mass of H₂O is 18.02 g/mol.
45 mol × 18.02 g/mol = 8.1 × 10² g
