Answer:
Explanation:
To determine the age, we need to know how much U have become Pb, so first we have to calculate the Pb moles present in a sample:
The percentage of U degradation:
Assuming that the life time is linear:
Answer:
fossil fuel combustion
Explanation:
Fossil fuel is the source of energy that drives almost all industrial processes on the surface of earth. Burning of these fuels releases energy for use in automobiles, industries, homes e.t.c. The complete combustion of these fuels in the presence of oxygen liberates carbon-dioxide and water with heat energy.
Fossil fuels are to a large extent hydrocarbon compounds and their derivatives. They form from organisms million of years ago. When organic matter is prevented from decay in an oxic or oxygen rich environment, they are able to conserve and preserve the energy in them for a vast duration in geologic time. This preserved energy is what becomes available during combustion.
Some of the fossil fuels are oil, natural gas, coal, e.t.c.
Percent error=(experimentally determined boiling point-actual boiling point)
=(124.1 - 125.7) = 1.6 °C
Quantity Number of significant figures
0.070020 meter 5
10,800 meters 5
0.010 square meter 2
5.00 cubic meters 1
507 thumbtacks 3
(5.3 x 10⁴) + (1.3 x 10⁴) =6.6 x 10⁴
(7.2 x 10⁻⁴) ÷ (1.8 x 10³)=4 x 10⁻⁷
10⁴ x 10⁻³ x 10⁶=10⁷
(9.12 x 10⁻¹) - (4.7 x 10⁻²)=(9.12 x 10⁻²) - (4.7 x 10⁻²)
=(91.2-4.7) x 10⁻²
=85.5 x 10⁻²
The answer is wood burring it causes smoke which worsens the air <span />