Answer:
in a chemical reaction, the mass of the products will always be equal to the mass of the reactants.
Explanation:
Answer:
= 72900 years
Explanation:
- The half-life is the time taken by a radioactive material to decay by half the original amount.
- The half-life of plutonium-239 is 24300 years which means it takes 24300 years to decay by half the original amount.
To calculate the time taken for a mass of 8 kg to decay to 1 kg we use;
New mass = Original mass x (1/2) ^n, where n is the number of half-lives
Therefore;
1 kg = 8 kg × (1/2)^n
1/8 = (1/2)^n
solving for n;
n =3
Therefore;
Time = 3 × 24300 years
= 72900 years
It will, therefore, take 72900 years for 8 kg of plutonium-239 to decay to 1 kg.
Answer:
Explanation:
1. Miles travelled in an average month

2. Using a gasoline powered vehicle
(a) Moles of heptane used
(b) Equation for combustion
C₇H₁₆ + O₂ ⟶ 7CO₂ + 8H₂O
(c) Moles of CO₂ formed
(d) Volume of CO₂ formed
At 20 °C and 1 atm, the molar volume of a gas is 24.0 L.
3. Using an electric vehicle
(a) Theoretical energy used

(b) Actual energy used
The power station is only 85 % efficient.

(c) Combustion of CH₄
CH₄ + 2O₂ ⟶ CO₂ +2 H₂O
(d) Equivalent volume of CO₂
The heat of combustion of methane is -802.3 kJ·mol⁻¹

4. Comparison

An enema administration is a technique used to stimulate stool evacuation The process helps push waste out of the rectum when you cannot do so on your own
Isotope 1: 89.905 * 51.45 = 4625.61225 / 100 = 46.2561225
Isotope 2: 90.906 * 11.22 = 1019.96532 / 100 = 10.1996532
Isotope 3: 91.905 * 17.15 = 1576.17175 / 100 = 15.7617075
Isotope 4: 93.906 * 17.38 = 1632.08628 / 100 = 16.3208628
Isotope 5: 95.908 * 2.08 = 268.5424 / 100 = 2.685424
46.2561225 + 10.1996532 + 15.7617075 + 16.3208628 + 2.685424 = 91.22377
actual mass Zr = about 91.22