All categories

3 years ago

7. Which two substances do geologists use in radiocarbon dating?

Chemistry

1 answer:

Sav [38]3 years ago

7 0

Carbon -14 and Carbon 12 are the two substances geologists use in radiocarbon dating.

Answer: Option B

<u>Explanation: </u>

Radiocarbon dating denotes the determination process of the age of fossils of plants or animals based on the ratio of carbon atoms 14 to 12. Carbon naturally exists in two non-radioactive isotopes, Carbon-12 and Carbon-13 and one radioactive isotope carbon 14. The carbon 14 gets released on continuous cosmic reaction with atmospheric nitrogen.

These carbon 14 will be absorbed by the living plants and from the plants. Then, it will enter inside the animals which consume the plants. But once the plants and animals died, they ceased to intake carbon-14. In their living state, the ratios of carbon atoms 14 to 12 in them tends to similar to the ratio in atmosphere.

But after they die, the ratio of C-14 to C-12 will be varying from the ratio of C-14 to C-12 in atmosphere as the concentration of C-14 will be decreasing in the dead animals and plants. Thus using this ratio, geologists can find the fossil's age.

You might be interested in

Phosgene is formed from carbon monoxide and chlorine. At 611 oC, Kc is approximately 16.5 M-1 or L/mol. Calculate Kp (in atm-1)

defon

Answer:

Kp is 0.228/atm

Explanation:

This is the reaction:

CO + Cl<u>₂</u> → CCl₂O

1 mol of carbon monoxide and 1 mol of chlorine produce 1 mol of phosgene.

Formula for Kp which derivates from Kc is:

Kp = Kc (R.T)ⁿᵇ ⁻ ⁿᵃ

Δп = nb (moles in the products) - nₐ(moles in the reactants)

Δп = 1 - 2 = -1

T is T° in K → T°C + 273 = 611°C +273 = 884K

R → Universal constant gas → 0.082 L.atm/mol.K

We replace the data: Kp = 16.5 L/mol (0.082 . 884K)⁻¹ → 0.228/atm

5 0

3 years ago

Which of these did your answer include?

sveticcg [70]

The oxygen atom has a partial negative charge and the Hydrogen atoms have a partial positive charge

8 0

3 years ago

4. Why does the amount of heat released or absorbed in these processes change over time?

icang [17]

Answer:

aksisksiiskkssiososossozoozso

8 0

3 years ago

Calculate the volumetric size of a water molecule in water vapor at normal conditions, assuming 1 mole of the vapor occupies 22.

Vedmedyk [2.9K]

Let volumetric size of a water molecule = v

Since, 1 mole of water consists of $6.023\times 10^{23}$ molecules of water.

Thus, total volume of 1 mole of water = $volumetric size \times 6.023\times 10^{23}$

Substitute the value of total volume of 1 mole of water i.e. 22.4 L in above formula.

$22.4 L = v\times 6.023\times 10^{23}$

$v= \frac{22.4 L}{6.023\times 10^{23}}$

Convert the unit litre to angstrom

$v=\frac{22.4 L}{6.023\times 10^{23}}\times \frac{1dm^{3}}{1L}\times \frac{(10^{9})^{3}(A^{o})^{3}}{1 dm^{3}}$

= $3.7\times 10^{-23}\times 10^{27} (A^{o})^{3}$

= $3.7 \times 10^{4}(A^{o})^{3}$

Therefore, the volumetric size of the water molecule is $3.7 \times 10^{4}(A^{o})^{3}$

8 0

3 years ago

If one starts with pure NO2(g) at a pressure of 0.500 atm, the total pressure inside the reaction vessel when 2 NO2(g) ⇌ 2 NO(g)

Anni [7]

Answer:

The equilibrium partial pressure of NO2 is 0.152 atm

Explanation:

Step 1: Data given

Initial pressure of NO2 = 0.500 Atm

Total pressure inside the vessel at equilibrium = 0.674 atm

Step 2: The balanced equation

2 NO2(g) ⇌ 2 NO(g) + O2(g)

Step 3: The initial pressures

pNO2 = 0.500 atm

pNO = 0 atm

pO2 = 0 atm

Step 4: The pressure at the equilibrium

pNO2 = 0.500 - 2x

pNO = 2x

pO2 = x

Total pressure = 0.674 = (0.500 - 2x) + 2x + x

0.674 = 0.500 + x

x = 0.174

pNO2 = 0.500 - 2*0.174 = 0.152 atm

pNO = 2x = 0.348 atm

pO2 = x = 0.176 atm

The equilibrium partial pressure of NO2 is 0.152 atm

4 0

3 years ago