physical change in a substance doesn't change what the substance is. In a chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed. For example, if a piece of paper is cut up into small pieces it still is paper.
You can find an element's amount of energy level by determining their place on the periodic table. An element's amount of energy levels are represented by which period/ row they are in. For example, Calcium has 4 energy levels. I know this because it is in the fourth period on the table.
Hope this helps!
N=N₀*2^(-t/T)
N₀=200 g
T=10 d
t=30 d
N=200*2^(-30/10)=25 g
25 g will remain
Answer:
0.683 moles of the gas are required
Explanation:
Avogadro's law relates the moles of a gas with its volume. The volume of a gas is directely proportional to its moles when temperature and pressure of the gas remains constant. The law is:
V₁n₂ = V₂n₁
<em>Where V is volume and n are moles of 1, initial state and 2, final state of the gas.</em>
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Computing the values of the problem:
1.50Ln₂ = 5L*0.205mol
n₂ = 0.683 moles of the gas are required
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