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2 years ago

Which of the following items represents a chemical change?

Chemistry

1 answer:

4vir4ik [10]2 years ago

7 0

Burning is a chemical reaction

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What effect does a catalyst have on a reaccion rate an the products formed in a reaccion

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A catalyst will speed up the activation energy and therefore speed up the reaction. The products will form fast because of this.

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2 years ago

Which geoiogic feature is most likey to from a mid

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4 years ago

What is the ionic charge for the calcium ion in CaCO3?

Lunna [17]

<span>The ionic charge of Calcium (Ca) in calcium carbonate (CaCO3) is 2+. CaCO3 has a neutral ionic charge sin CO3 has a 2- charge.</span>

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3 years ago

Carbon-14 is a radioactive isotope that decays according to first-order kinetics in a process that has a half-life of 5730 years

Sliva [168]

Answer : The time passed in years is $2.83\times 10^3\text{ years}$

Explanation :

Half-life = 5730 years

First we have to calculate the rate constant, we use the formula :

$k=\frac{0.693}{t_{1/2}}$

$k=\frac{0.693}{5730\text{ years}}$

$k=1.21\times 10^{-4}\text{ years}^{-1}$

Now we have to calculate the time passed.

Expression for rate law for first order kinetics is given by:

$t=\frac{2.303}{k}\log\frac{a}{a-x}$

where,

k = rate constant = $1.21\times 10^{-4}\text{ years}^{-1}$

t = time passed by the sample = ?

a = let initial amount of the reactant = X g

a - x = amount left after decay process = $71\% \times (x)=\frac{71}{100}\times (X)=0.71Xg$

Now put all the given values in above equation, we get

$t=\frac{2.303}{1.21\times 10^{-4}}\log\frac{X}{0.71X}$

$t=2831.00\text{ years}=2.83\times 10^3\text{ years}$

Therefore, the time passed in years is $2.83\times 10^3\text{ years}$

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3 years ago

Explain why neon is monatomic but chlorine is diatomic.

Elza [17]

Chlorine is a halogen and all halogens and oxygen, nitrogen and hydrogen are diatomics

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3 years ago

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