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3 years ago

How do the atomic number and the

Chemistry

1 answer:

Tomtit [17]3 years ago

4 0

Answer:

It's the first option.

Explanation:

The atomic number tells us the number of protons in the nucleus of an atom.

It is the number which identifies an atom.

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Charcoal found under a stone at Stonehenge, England, has a carbon-14 activity that is 0.60 that of new wood. How old is the char

kenny6666 [7]

Charcoal with a carbon-14 activity of 0.60 compared to new wood has less than 5,730 years.

<h3>What is a radioactive isotope?</h3>

A radioactive isotope is an element in nature that emit radioactivity in a given period of time (e.g., the half-life for C14 is equal to 5,730 years).

Radioactive dating is a technique to measure the age of an element by measuring its radioactive activity.

In conclusion, charcoal with a carbon-14 activity of 0.60 compared to new wood has less than 5,730 yr.

Learn more about radioactive dating here:

brainly.com/question/8831242

#SPJ1

5 0

1 year ago

A sample of gas is observed to effuse through a pourous barrier in 4.98 minutes. Under the same conditions, the same number of m

kogti [31]

Answer:

The molar mass of the unknown gas is $\mathbf{ 51.865 \ g/mol}$

Explanation:

Let assume that the gas is O2 gas

O2 gas is to effuse through a porous barrier in time t₁ = 4.98 minutes.

Under the same conditions;

the same number of moles of an unknown gas requires time t₂ = 6.34 minutes to effuse through the same barrier.

From Graham's Law of Diffusion;

Graham's Law of Diffusion states that, at a constant temperature and pressure; the rate of diffusion of a gas is inversely proportional to the square root of its density.

i.e

$R \ \alpha \ \dfrac{1}{\sqrt{d}}$

$R = \dfrac{k}{d}$ where K = constant

If we compare the rate o diffusion of two gases;

$\dfrac{R_1}{R_2}= {\sqrt{\dfrac{d_2}{d_1}}$

Since the density of a gas d is proportional to its relative molecular mass M. Then;

$\dfrac{R_1}{R_2}= {\sqrt{\dfrac{M_2}{M_1}}$

Rate is the reciprocal of time ; i.e

$R = \dfrac{1}{t}$

Thus; replacing the value of R into the above previous equation;we have:

$\dfrac{R_1}{R_2}={\dfrac{t_2}{t_1}}$

We can equally say:

${\dfrac{t_2}{t_1}}= {\sqrt{\dfrac{M_2}{M_1}}$

${\dfrac{6.34}{4.98}}= {\sqrt{\dfrac{M_2}{32}}$

$M_2 = 32 \times ( \dfrac{6.34}{4.98})^2$

$M_2 = 32 \times ( 1.273092369)^2$

$M_2 = 32 \times 1.62076418$

$\mathbf{M_2 = 51.865 \ g/mol}$

7 0

2 years ago

Atom X contains nine protons and seven neutrons. Atom Z contains nine protons and eight neutrons. Which of the following stateme

MrRissso [65]

I thinks the it is question A.

5 0

2 years ago

Select the correct answer. Which subatomic particle is electrically neutral and found in the nucleus of an atom? A. proton B. ne

rodikova [14]

<u>Answer:</u> The correct answer is Option B.

<u>Explanation:</u>

There are 3 subatomic orbitals which are present in an atom:

1. Protons: These sub-atomic particles are positively charged and are found in the nucleus.

2. Electrons: These sub-atomic particles are negatively charged and are found in the orbitals around the nucleus.

3. Neutrons: These sub-atomic particles carry no charge and are known as electrically neutral species. These particles are found in the nucleus.

From the above information, the answer to this question is Option B.

8 0

3 years ago

A closed tank is partially filled with seawater with density 1,030 kg/m3. If the pressure in the tank's airspace is 32 kPa and t

Alexandra [31]

Answer:

The pressure at the bottom is 122 kPa or 17.7 psi.

Explanation:

The pressure at the bottom is equal to the pressure of the airspace plus the pressure of the seawater.

Pbottom = Pairspace + Pseawater [1]

The pressure caused by the column of seawater can be calculated using the expression:

Pseawater = ρ . g . h [2]

where,

ρ is the density of the seawater

g is the gravity (9.87 m/s²)

h is the depth of the seawater column

Solving [2]:

Pseawater = 1,030 kg/m³ x 9.87 m/s² x 9 m = 9 x 10⁴ kg/m.s² = 9 x 10⁴ Pa

$Pseawater=9\times 10^{4} Pa.\frac{1kPa}{10^{3}Pa } =90kPa$

Then, we use this result in [1]:

Pbottom = Pairspace + Pseawater

Pbottom = 32 kPa + 90 kPa = 122 kPa

We can express this result in psi, knowing that 1 psi = 6.89 kPa.

$122kPa.\frac{1psi}{6.89kPa} =17.7psi$

6 0

3 years ago