Because 25% is half of 0.5 and the half life of 
is given as 5,715, the time it takes to reach this amount should just be double the half life: 11430 years.
However, in other cases the problem may not have easy numbers, so below is a more mathematical approach.
The half life formula is 
.
Solving for t gives:
Given information:
Plug in given values and solve for t.
With correct significant figures, this would be 11000 years.
As water freezes its molecules move farther apart. As when water freezes , Its move farther apart .
And the cause of this movement is hydrogen bond that is formed among the surrounding water molecules that causes water molecules to move apart. So as water freezes its molecules move farther apart, it is the correct answer .
Answer: left and right hemisphere ya
Explanation:
Answer:
Explanation:
A <em>combustion reaction</em> is the reaction with oxygen along with the release of energy in form of heat or light.
Organic compounds (like CH₄) undergo combustion forming water and CO₂.
The combustion reaction of CH₄ is:
Hence, the first equation from the choices is not showing the combustion reaction of CH₄.
Not only organic compounds can undergo combustion. Metals and no metals can undergo combustion, i.e. metals and no metals can react with oxygen releasing light or heat.
The reaction of copper and oxygen (second choice) is a combustion reaction:
The formation of water (2H₂ + O₂ → 2H₂O) is other example of a combustion reaction where no organic compounds are involved.
On the other hand, the other two equations from the choice list are not reactions with oxygen, so they do not show combustion reactions.
- Answer:
Energy release is exothermic reaction whiles energy absorb is endothermic reaction
Explanation:
Exothermic reaction is when the reactant is above the product while endothermic the product is below the reactant in the diagrams we have some part as activation energy
