The amount of radioactive carbon-14 in a sample is measured using a Geiger counter, which records each disintegration of an atom. Living tissue disintegrates at a rate of about 13.5 atoms per minute per gram of carbon. In 1977 a charcoal fragment found at Stonehenge, England, recorded 8.2 disintegrations per minute per gram of carbon. Assuming that the half-life of carbon14 is 5730 years and that the charcoal was formed during the building of the site, estimate the date when Stonehenge was built

Answer:

mass = 102.69 g of sucrose

Explanation:

First, you need to use the correct expression of molality (m) which is the following:

m = moles / kg solvent    (1)

According to the exercise, we need to get the grams, in other words, the mass of the sucrose. To get the mass, we need the moles and molecular weight of sucrose and use the following expression:

moles = mass / MM    (2)

Now, if we replace (2) in (1) we have:

m = mass / MM * kg solvent   (3)

From here, we solve for the mass and then:

mass = m * MM * kg solvent (4)

Now, then density of water is 1 kg/L, so, the volume of the water will be the same as it's mass, and the molality is 3 m. The molecular weight of the sucrose is (according to several sources) 342.3 g/mol. Replacing all the data in (4) we have:

mass = 3 mol/kg * 0.1 kg * 342.3 g/mol

Hope this helps

Answer:

[tex]v_{solute}=25mL[/tex]

Explanation:

Hello there!

In this case, according to the by-volume concentration of this solution, it is possible for us to use its mathematical definition as shown below:

[tex]\%v=\frac{v_{solute}}{v_{solution}}*100\%[/tex]

Thus, given the percent and the volume of the solution, we can solve for the volume of ethanol (solute) as shown below:

[tex]v_{solute}=\frac{\%v*v_{solution}}{100\% }\\\\v_{solute}=\frac{5.00\%*500mL}{100\%}\\\\ v_{solute}=25mL[/tex]

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Answer:

Option C, an elongated ridge designed by engineers that runs parallel to a stream channel

Explanation:

A natural or artificial levee is basically a ridge constructed along a river bank to regulate the water level in the stream.

It run along the river embankment and hence can be said that it runs parallel to the river length

Hence, option C is correct

Answer:

here :). hope this helps.

Answer:

segmented bodies, jointed appendages, & exoskeleton

Explanation:

Hope you succeed, have a nice day!

Answer:

691.7 mmHg is the resulting pressure

Explanation:

Tha Gay-Lussac's law states that the pressure of a gas is directly proportional to its absolute temperature under constant volume. The equation is:

P1T2 = P2T1

Where P is pressure and T asbolute temperature of 1, initial state and 2, final state of the gas.

Computing the values of the problem:

T1 = 273 + 25 = 298K

P1 = 755.0mmHg

T2 = 273 + 0 = 273K

P2 = ?

755.0mmHg*273K = P2*298K

Explanation:

What's Your Question ??..

Answer:

4 liters I think actually hold on

Answer:

( dichlorine monoxide ) is Polar Explanation:Answer. Answer = CF2Cl2 (Dichlorodifluoromethane) is Polar What is polar and non-polar? Cl2O ( dichlorine monoxide ) is Polar I'll tell you the polar or nonpolar list below.

Answer:

V ≈ 16,662.63 L

Explanation:

The data given in the question includes;

The pressure in the medium, P = 1.23 mmHg

The number of moles of the substance present in the medium, n = 0.773 mol

The temperature of the substance in the medium, T = 152 °C = 425.15 K

The unknown quantity, V = The volume filled by the substance

The ideal gas law equation that can be used to find the unknown volume is given here as follows;

P × V = n × R × T

Where;

R = The Universal Gas Constant = 62.363 mmHg·L·mol⁻¹·K⁻¹

From the ideal gas law equation, we get;

V = n × R × T/P

Plugging in the values, gives;

V = 0.773 mol × 62.363 mmHg·L·mol⁻¹·K⁻¹ × 425.15 K/(1.23 mmHg) = 16,662.6305405 L

The volume occupied, which is the unknown quantity, V ≈ 16,662.63 L.

Answer:

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Answer:

3) Vapor pressure in atm = 0.13 atm

Explanation:

Answer:

microwaves

Explanation:

Microwaves and radio waves are the longest wavelengths while the shortest are gamma rays and x-rays

Explanation:

can you tell us what do want help with?

Answer:

Ok I will give you answer

Answer:

A)20.0grams

Explanation:

Answer:

10

Explanation:

Answer:

colorless liquid with a strong smell and a white solid with no smell. The substances’ repeating groups of atoms are shown above on the left. After they were mixed, the chemist analyzed the results and found two substances. One ending substance had the repeating group of atoms shown above on the right.

Explanation:

Answer:

2.3 L

Explanation:

A change in pressure-volume at constant temperature is described by the Boyle's law. The mathematical relationship between initial pressure and volume (P₁ and V₁) and final pressure and volume (P₂ and V₂) is given by:

P₁V₁ = P₂V₂

We have the following data:

initial pressure: P₁= 2.5 atm

initial volume: V₁ = 9.1 L

final pressure: P₂= 9.8 atm

Thus, we introduce the data in the mathematical expression and calculate the final volume V₂, as follows:

V₂ = P₁V₁/P₂ = (2.5 atm x 9.1 L)/9.8 atm = 2.3 L

Therefore, the volume of the canister is 2.3 L.

Answer:

The right answer is "0.17 M".

Explanation:

The given values are:

Volume,

V₁ = 250 mL

V₂ = 750 mL

Molarity,

M₁ = 0.50 M

M₂ = ?

As we know,

⇒  [tex]M_1 V_1=M_2 V_2[/tex]

or,

⇒  [tex]M_2=\frac{M_1 V_1}{V_2}[/tex]

On substituting the values, we get

⇒        [tex]=\frac{0.50\times 250}{750}[/tex]

⇒        [tex]=\frac{125}{750}[/tex]

⇒        [tex]=0.17 \ M[/tex]

Answer:

1.385 x 1025 molecules are there in 23 mole of oxygen

Answer:

mesosphere

I hope this helps a little bit.

Answer:

30.34 atm

Explanation:

Using the general gas law formula;

PV = nRT

Where;

P = pressure (atm)

V = volume (L)

n = number of moles (mol)

T = temperature (K)

R = gas law constant (0.0821 Latm/molK)

According to the information provided in this question,

n = 3mol

T = 35°C = 35 + 273 = 308K

V = 2.5L

P = ?

Using PV = nRT

P = nRT/V

P = 3 × 0.0821 × 308/2.5

P = 75.8604 ÷ 2.5

P = 30.34 atm.

. Its nucleus is unstable.

Its nucleus is unstable. This characterizes a radioactive atom. Therefore, the correct option is option A.

The smallest parts of common stuff that can be separated without releasing electrically charged particles are called atoms. The atoms are divided into two sections. an electron cloud and an atomic nucleus. Atoms with an unstable nucleus and the potential for radioactive decay are referred to as radioactive atoms.

As only nuclei often experience decay and changes with electron configuration only come from nucleus configuration changes, the term "radioactive atom" is misleading. This isn't a rule, it must be said. As a parent nucleus needs capture any of its orbital electrons, the electron cloud also plays a significant role in the case of electron capture. Its nucleus is unstable. This characterizes a radioactive atom.

Therefore, the correct option is option A.

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Answer:

Answer:

–253.5 °C

Explanation:

We'll begin by calculating the number of mole in 6 g of CO₂. This can be obtained as follow:

Molar mass of CO₂ = 12 + (2×16)

= 12 + 32

= 44 g/mol

Mass of CO₂ = 6 g

Mole of CO₂ =.?

Mole = mass / molar mass

Mole of CO₂ = 6 / 44

Mole of CO₂ = 0.136 mole

Next, we shall convert 225 mL to L.

1000 mL = 1 L

Therefore,

225 mL = 225 mL × 1 L / 1000

225 mL = 0.225 L

Next, we shall determine the temperature of the gas. This can be obtained as follow:

Pressure (P) = 0.855 atm

Volume (V) = 0.225 L

Number of mole (n) = 0.136 mole

Gas constant (R) = 0.0821 atm.L/Kmol

Temperature (T) =?

PV =nRT

0.855 × 0.255 = 0.136 × 0.0821 × T

0.218025 = 0.0111656 × T

Divide both side by 0.0111656

T = 0.218025 / 0.0111656

T = 19.5 K

Finally, we shall convert 19.5 K to degree celsius (°C). This can be obtained as follow:

T(°C) = T(K) – 273

T(K) = 19.5 K

T(°C) = 19.5 – 273

T(°C) = –253.5 °C

Therefore, the temperature of the gas is –253.5 °C

Explanation:

It explodes when a spark is present.. letter D

Answer:

A. It is flammable.

Explanation:

physical property is a characteristic of matter that is not associated with a change in its chemical composition. Familiar examples of physical properties include density, color, hardness, melting and boiling points, and electrical conductivity.

Answer:

Explanation:

It comes in different colors, it expands when it's "full". It floats away if it is not tied down and will make a loud noise if it pops (breaks).

Answer:

There are now two oxygen atoms on the left and four on the right (in one N2O and three H2O's), so we balance the oxygen atoms by placing a 2 in front of the O2.

The numbers before atoms are the coefficients, and they are used to balance chemical reacions. In the provided example, number in front of O₂ is 3.

Note: Since I do not have the proposed reaction, I provided a random example.

A balanced chemical reaction is an equation in which the number and type of atoms are the same on both sides of the arrows.

Following the law of mass conservation, chemical equations should be balanced to ensure that all the reactants appear in the products.

This means that no new atoms appear, and no atoms disappear. The only thing that changes in a chemical reaction is the bond between atoms.

So each side of the equation must be equilibrated concerning the amount and type of atoms.

Coefficients are used to balance reactions. These numbers are located before each atom and indicate the number of units present in the formula.

I do not have the proposed reaction, but I will provide an example using O₂.

Reactants ⇒ 4 Al and 3 O₂

                     3 O₂ = 6 O

Products ⇒ 2 Al₂O₃

                    2 Al₂ = 4 Al

                    2 O₃ = 6 O

On each side of the equation we have 4 Al and 6 O. The only thing that changes are the bonds between atoms.

In this case, the coefficient of O₂ is 3.

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