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3 years ago

Element 2 is: A) Cobalt B)Chlorine C)Calcium D)Carbon

Chemistry

1 answer:

saul85 [17]3 years ago

4 0

Answer:

D: Carbon

Explanation:

Carbon is the sixth element with a total of 6 electrons in the periodic table. Hence the atomic number Z = 6. The ground state electron configuration of carbon is 1s2 2s2 2p2. An excited state electron configuration of carbon is 1s2 2s1 2p3.

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A large cyclotron directs a beam of He++ nuclei onto a target with a beam current of 0.250 mA. (a) How many He++ nuclei per seco

nikitadnepr [17]

Answer:

a. 7.8*10¹⁴ He⁺⁺ nuclei/s

b. 4000s

c. 7.7*10⁸s

Explanation:

I = 0.250mA = 2.5 * 10⁻³A

Q = 1.0C

1 e- contains 1.60 * 10⁻¹⁹C

But He⁺⁺ Carrie's 2 charge = 2 * 1.60*10⁻¹⁹C = 3.20*10⁻¹⁹C

(A).

No. Of charge per second = current passing through / charge

1 He⁺⁺ = 2.50 * 10⁻⁴ / 3.2*10⁻¹⁹C

1 He⁺⁺ = 7.8 * 10¹⁴ He⁺⁺ nuclei

(B).

I = Q / t

From this equation, we can determine the time it takes to transfer 1.0C

I = 1.0 / 2.5*10⁻⁴ = 4000s

(C).

Time it takes for 1 mol of He⁺⁺ to strike the target =?

Using Avogadro's ratio,

1.0 mole of He = (6.02 * 10²³ ions/mol ) * (1 / 7.81*10¹⁴ He ions)

Note : ions cancel out leaving the value of the answer in mols.

1.0 mol of He = 7.7 * 10⁸s

8 0

3 years ago

Provide the name(s) for the tertiary alcohol(s) with the chemical formula C6H14O that have a 4-carbon chain. Although stereochem

pochemuha

Answer:

Explanation:

A tertiary alcohol is a compound (an alcohol) in which the carbon atom that has the hydroxyl group (-OH) is also bonded (saturated) to three different carbon atoms.

Based on the question, the only <u>tertiary alcohol that can result from C₆H₁₄O that have a 4-carbon chain</u> is

2-hydroxy-2,3-dimethylbutane

H OH H H

| | | |

H - C - C - C - C - H

| | | |

H CH₃ CH₃ H

From the above, we can see that the carbon atom having the hydroxyl group is also bonded to three other carbon atoms. And since we aren't considering stereochemistry, this is the only tertiary alcohol we can have with a 4-carbon chain

4 0

3 years ago

Sort these species into isoelectronic groups. It doesn\'t matter which group goes in which box, so long as the correct species a

OleMash [197]

Answer : The isoelectronic groups are:

$He,Be^{2+},Li^{+}$

$N^{3-},Mg^{2+}$

$S^{2-},Ti^{4+},K^{+}$

Explanation :

Isoelectronic : It is defined as the compound or molecule having the same number of electrons and the same number of electronic structure.

The element is helium. The number of electrons are 2.
The element is beryllium. The number of electrons are 4. The number of electrons in $Be^{2+}$ = 4 - 2 = 2
The element is lithium. The number of electrons are 3. The number of electrons in $Li^{+}$ = 3 - 1 = 2
The element is nitrogen. The number of electrons are 7. The number of electrons in $N^{3-}$ = 7 + 3 = 10
The element is neon. The number of electrons are 10.
The element is sulfur. The number of electrons are 16. The number of electrons in $S^{2-}$ = 16 + 2 = 18
The element is magnesium. The number of electrons are 12. The number of electrons in $Mg^{2+}$ = 12 - 2 = 10
The element is titanium. The number of electrons are 22. The number of electrons in $Ti^{4+}$ = 22 - 4 = 18
The element is potassium. The number of electrons are 19. The number of electrons in $K^{+}$ = 19 - 1 = 18

The isoelectronic groups are:

$He,Be^{2+},Li^{+}$

$N^{3-},Mg^{2+}$

$S^{2-},Ti^{4+},K^{+}$

7 0

3 years ago

Hydrogen peroxide is a powerful oxidizing agent; it is used in concentrated solution in rocket fuel and in dilute solution in ha

Anestetic [448]

The molarity of the hydrogen peroxide solution from the information supplied in the question is 12.26 M.

Co = 10pd/M

Where;

Co = concentration = ?

p = percent of the hydrogen peroxide = 30%

d = Density of hydrogen peroxide = 1.39 g/ml

M = Molar mass = 34 g/mol

Substituting values;

Co = 10 × 30 × 1.39/34

Co = 12.26 M

The molarity of the hydrogen peroxide solution from the information supplied in the question is 12.26 M.

Learn more: brainly.com/question/6111443

4 0

2 years ago

Under identical conditions, separate samples of O2 and an unknown gas were allowed to effuse through identical membranes simulta

scoray [572]

Answer:

70.77 g/mol is the molar mass of the unknown gas.

Explanation:

Effusion is defined as rate of change of volume with respect to time.

Rate of Effusion= $\frac{Volume}{Time}$

Effusion rate of oxygen gas after time t = $E=\frac{4.64 mL}{t}$

Molar mass of oxygen gas = M = 32 g/mol

Effusion rate of unknown gas after time t = $E'=\frac{3.12 mL}{t}$

Molar mass of unknown gas = M'

The rate of diffusion of gas, we use Graham's Law.

This law states that the rate of effusion or diffusion of gas is inversely proportional to the square root of the molar mass of the gas. The equation given by this law follows:

$\text{Rate of effusion}\propto \frac{1}{\sqrt{\text{Molar mass of the gas}}}$

$\frac{E}{E'}=\sqrt{\frac{M'}{M}}$

$\frac{\frac{4.64 mL}{t}}{\frac{3.12 mL}{t}}=\sqrt{\frac{M'}{32 g/mol}}$

M' = 70.77 g/mol

70.77 g/mol is the molar mass of the unknown gas.

8 0

3 years ago