Which of the following represents the molecules of one compound and atoms of one element?

The half-life of a radioactive isotope is the amount of time it takes for a quantity of that isotope to decay to one half of its

Sedaia [141]

Radio active decay reactions follow first order rate kinetics.

a) The half life and decay constant for radio active decay reactions are related by the equation:

$t_{\frac{1}{2}} =$ $\frac{ln 2}{k}$

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

Where k is the decay constant

b) Finding out the decay constant for the decay of C-14 isotope:

$Decay constant (k) = \frac{0.693}{t_{\frac{1}{2}}}$

$k = \frac{0.693}{5230 years}$

$k = 1.325 * 10^{-4} yr^{-1}$

c) Finding the age of the sample :

35 % of the radiocarbon is present currently.

The first order rate equation is,

$[A] = [A_{0}]e^{-kt}$

$\frac{[A]}{[A_{0}]} = e^{-kt}$

$\frac{35}{100} = e^{-(1.325 *10^{-4})t}$

$ln(0.35) = -(1.325 *10^{-4})(t)$

t = 7923 years

Therefore, age of the sample is 7923 years.

3 0

3 years ago

How many grams are in 562 dg? 56.2 g 56,200 g 5.620 g 5.62 g

lana66690 [7]

Answer:

56.2

Explanation:

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7 0

3 years ago

How is burning wood a good illustration of the law of conservation of mass?

crimeas [40]

The wood turns into ash and smoke so mass is nor destroyed or created.

6 0

2 years ago

Paradichlorobenzene, C6H4Cl2, is a component of mothballs. A solution of 2.00 g in 22.5 g of cyclohexane boils at 82.39 ∘C. The

Rina8888 [55]

Answer:

2.79 °C/m

Explanation:

When a nonvolatile solute is dissolved in a pure solvent, the boiling point of the solvent increases. This property is called ebullioscopy. The temperature change (ΔT) can be calculated by:

ΔT = Kb*W*i

Where Kb is the ebullioscopy constant for the solvent, W is the molality and i is the van't Hoff factor.

W = m1/(M1*m2)

Where m1 is the mass of the solute (in g), M1 is the molar mass of the solute, and m2 is the mass of the solvent (in kg).

The van't Hoff factor represents the dissociation of the elements. For an organic molecule, we can approximate i = 1. Thus:

m1 = 2.00 g

M1 = 147 g/mol

m2 = 0.0225 kg

W = 2/(147*0.0225)

W = 0.6047 mol/kg

(82.39 - 80.70) = Kb*0.6047*1

0.6047Kb = 1.69

Kb = 2.79 °C/m

4 0

3 years ago

Which of the following is the largest volume?

Artist 52 [7]

I will use this conversion:

1m = 1000 mm => 1 = 1m / 1000mm

1 m = 100 cm=> 1 = 1m / 100cm

1m = 10 dm=> 1 = 1m / 10 dm

So,

B) 3.8 * 10^7 cm^3 = 3.8 * 10^7 cm^3 * [1m / 100cm]^3 = 38 m^3

C) 3.8 * 10^5 dm^3 * [1m / 10 dm]^3 = 380 m^3

D) 3.8 * 10^8 mm^3 * [1m / 1000 mm]^3 = 0.38 m^3

Now you can compare the four volumes and conclude which is the largest.

Answer: option C) 3.8 * 10^5 dm^3

5 0

3 years ago