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ale4655 [162]
3 years ago
8

Find the age t of a sample, if the total mass of carbon in the sample is mc, the activity of the sample is a, the current ratio

of the mass of 14 6c to the total mass of carbon in the atmosphere is r, and the decay constant of 14 6c is λ. assume that, at any time, 14 6c is a negligible fraction of the total mass of carbon and that the measured activity of the sample is purely due to 14 6c. also assume that the ratio of mass of 14 6c to total carbon mass in the atmosphere (the source of the carbon in the sample) is the same at present and on the day when the number of 14 6c atoms in the sample was set. express your answer in terms of the mass ma of a 14 6c atom, mc, a, r, and λ.
Chemistry
1 answer:
Paha777 [63]3 years ago
6 0
N₀ is the number of C-14 atoms per kg of carbon in the original sample at time = Os when its carbon was of the same kind as that present in the atmosphere today. After time ts, due to radioactive decay, the number of C-14 atoms per kg of carbon is the same sample which has decreased to N. λ is the radioactive decay constant.
Therefore N = N₀e-λt which is the radioactive decay equation,
N₀/N = eλt In (N₀.N= λt. This is the equation 1
The mass of carbon which is present in the sample os mc kg. So the sample has a radioactivity of A/mc decay is/kg. r is the mass of C-14 in original sample at t= 0 per total mass of carbon in a sample which is equal to [(total number of C-14 atoms in the sample at t m=m 0) × ma]/ total mass of carbon in the sample.
Now that the total number of C-14 atoms in the sample at t= 0/ total mass of carbon in sample = N₀ then r = N₀×ma
So N₀ = r/ma. this equation 2.
 The activity of the radioactive substance is directly proportional to the number of atoms present at the time.
Activity = A number of decays/ sec = dN/dt = λ(number of atoms of C-14 present at time t) = 
λ₁(N×mc). By rearranging we get N = A/(λmc) this is equation 3.
By plugging in equation 2 and 3 and solve t to get
t = 1/λ In (rλmc/m₀A).

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In the word equation, sodium oxide water sodium hydroxide, the formula for sodium hydroxide is represented by
d1i1m1o1n [39]
Answer:
            <span>Formula for sodium hydroxide is represented by <u>NaOH</u>.

Explanation:
                     The reaction of Sodium oxide with water is as follow,

                               Na</span>₂O  +  H₂O    →    2 NaOH
<span>
Na</span>₂O is considered as a strong basic oxide as it contains O²⁻ which has high tendency to bind with hydrogen atoms. This reaction is an exothermic reaction and is conducted in cold water to produce NaOH.<span>

</span>
4 0
3 years ago
Use the drop-down menus to classify each of the following as an addition, substitution, elimination, or
OLga [1]

Answer:

CH3CHO+H2O → CH3OCH3 - addition

CH,CICH CI + Zn → C2H4 + ZnCl2 - elimination

CH3CH3Br + OH – CH3CH3OH + Br - substitution

2CH2COOH >>(CH3CO)20 + H20 - condensation

Explanation:

An addition reaction is a reaction in which a specie is added across the double bond as we can see in CH3CHO+H2O → CH3OCH3.

In an elimination reaction, a small molecule is lost from a saturated compound to form the corresponding unsaturated compound as in CH,CICH CI + Zn → C2H4 + ZnCl2

In a substitution reaction, a chemical moiety replaces another in a molecule as in; CH3CH3Br + OH – CH3CH3OH + Br .

A condensation reaction is in which two molecules are joined together to form a bigger molecule as in; 2CH2COOH >>(CH3CO)20 + H20.

4 0
3 years ago
How much CaCO3 would have to be decomposed to produce 247 g of CaO
vovangra [49]

441 g CaCO₃ would have to be decomposed to produce 247 g of CaO

<h3>Further explanation</h3>

Reaction

Decomposition of CaCO₃

CaCO₃ ⇒ CaO + CO₂

mass CaO = 247 g

mol of CaO(MW=56 g/mol) :

\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{247}{56}\\\\mol=4.41

From equation, mol ratio CaCO₃ : CaO = 1 : 1, so mol CaO :

\tt \dfrac{1}{1}\times 4.41=4.41

mass CaCO₃(MW=100 g/mol) :

\tt mass=mol\times MW\\\\mass=4.41\times 100\\\\mass=441~g

6 0
2 years ago
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The protons! Is it the answer
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How do the circulatory and the excretory systems work together to maintain the human body on a daily basis?
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The circulatory system picks up nitrogenous wastes from the cells and delivers them to the kidneys. The kidneys remove these wastes from the blood and concentrates them into the urine that is eliminated from the body.
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