Answer:
Explanation:
i don't know if this is 100% correct but i think it's inertia
The half-life of Th-232 is 1.405 × 10¹⁰ years
Time elapsed = 2.8 x 10⁹ years
Equation of radioactive decay:
A = A₀ = (1/2)^ t/t₁/₂
Thus, the percentage of thorium-232 in the rock that was dated at 2.8 billions year = 87.1%
Explanation:
Elements that belong to same group contains same number of valence electrons. Hence, they tend to show similar chemical properties.
When we move across a period then number of electrons get added to the same shell. As a result, there will be no increase in size of elements.
Also, metals are the elements that belong to group 1, 2 and d-block elements are also known as metals. Metallic character of elements decreases when we move left to right in a periodic table.
As most reactive metals are placed on the left side of periodic table.
Since, size of elements increases on moving down the group. So, an element is able to easily lose its valence electrons because of less force of attraction between its nucleus and valence electrons.
As a result, there will be increase in reactivity of metals on moving down the group.
Thus, we can conclude that given sentences are as follows.
- Elements in the same group have the same number of valence electrons.
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Elements in the same period have the same number of electron shells.
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Metallic elements become less reactive as you move left to right in a period.
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Metallic elements become more reactive as you move top to bottom in a group.
The major drawback of fossil fuels is that they warm the planet i.e. they cause global warming.
The reaction typically gives off heat and light as well. The general equation for a complete combustion reaction is:
Fuel + O2 → CO2 + H2O + ENERGY
<h3>
Disadvantages of Fossil fuels</h3>
The term "fossil fuels" refers to flammable organic geologic formations, including dead organic matter that has been buried hundreds of feet beneath sediment.
- Fossil fuel emissions include various oxides, such as carbon, nitrogen, and sulfate, which cause acid rain and harm the soil's fertility and water quality.
- Both coal and petroleum burning discharge a significant amount of pollutants into the atmosphere, contributing to pollution levels.
- Gases like carbon dioxide are released through the burning of fossil fuels, which aids in climate change.
To view similar questions on Fossil fuels, refer to:
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