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3 years ago

Why is pure silicon a poor conductor at room temperature?

1 answer:

Alex3 years ago

6 0

The appropriate answer is a. it's valence electrons are held tightly within the crystal structure. Metals are good conductors because they share electrons and so they are free to move about enabling it to be a good conductor. Any substance that has electrons tightly held within bonds will not be good conductors. If the structure of pure silicon had its valence electrons held loosely by a positive nucleus then it would be able to conduct.

You might be interested in

WHY ACETIC ACID IS STRONGER IN STRENGHT THAN CHLOROACETIC ACID ...?

aleksandr82 [10.1K]

For this question, I think it is the other way around. It is true that chloroacetic acid is stronger in strength than acetic acid. Acid strength is measured as the equilibrium constant of the reaction <span>HA -----> H+ + A-

</span><span> In acetic acid, the anion produced by dissociation is CH3-COO-; in chloroacetic acid it is CH2Cl-COO-. Comparing the two, in the first one the negative charge is taken up mostly by the two oxygen atoms. In the second there is also an electronegative chlorine atom nearby to draw more charge towards itself. Therefore, the charge is less concentrated in the chloroacetate ion than it is in the acetate ion, and, accordingly, chloroacetic acid is stronger than acetic acid. </span>

6 0

3 years ago

When a hydrochloric acid solution is combined with a potassium hydroxide solution, an acid-base reaction occurs. write a balance

Verizon [17]

Answer:

HCl(aq) + KOH(aq) ⇒ KCl(aq) + H₂O(l)

Explanation:

Hydrochloric acid is an acid because it releases H⁺ in an aqueous solution.

Potassium hydroxide is a base because it releases OH⁻ in an aqueous solution.

When an acid reacts with a base they form a salt and water. This is a neutralization reaction. The neutralization reaction between hydrochloric acid and potassium hydroxide is:

HCl(aq) + KOH(aq) ⇒ KCl(aq) + H₂O(l)

5 0

2 years ago

Given the reaction: solid sodium reacts with chlorine gas to form solid sodium chloride How many moles of the product result fro

lyudmila [28]

Answer:

number of moles of NaCl produce = 12 mol

Explanation:

Firstly, we need to write the chemical equation of the reaction and balance it .

Na(s) + Cl2(g) → NaCl(s)

The balanced equation is as follows:

2Na(s) + Cl2(g) → 2NaCl(s)

1 mole(71 g) of chlorine produces 2 moles(117 g) of sodium chloride

6 mole of chlorine gas will produce ? mole of sodium chloride

cross multiply

number of moles of NaCl produce = 6 × 2

number of moles of NaCl produce = 12 moles

number of moles of NaCl produce = 12 mol

3 0

3 years ago

The following data were obtained in a kinetics study of the hypothetical reaction A + B + C → products. [A]0 (M) [B]0 (M) [C]0 (

Vladimir [108]

Answer:

B. First order, Order with respect to C = 1

Explanation:

The given kinetic data is as follows:

A + B + C → Products

[A]₀ [B]₀ [C]₀ Initial Rate (10⁻³ M/s)

1. 0.4 0.4 0.2 160

2. 0.2 0.4 0.4 80

3. 0.6 0.1 0.2 15

4. 0.2 0.1 0.2 5

5. 0.2 0.2 0.4 20

The rate of the above reaction is given as:

$Rate = k[A]^{x}[B]^{y}[C]^{z}$

where x, y and z are the order with respect to A, B and C respectively.

k = rate constant

[A], [B], [C] are the concentrations

In the method of initial rates, the given reaction is run multiple times. The order with respect to a particular reactant is deduced by keeping the concentrations of the remaining reactants constant and measuring the rates. The ratio of the rates from the two runs gives the order relative to that reactant.

Order w.r.t A : Use trials 3 and 4

$\frac{Rate3}{Rate4}= [\frac{[A(3)]}{[A(4)]}]^{x}$

$\frac{15}{5}= [\frac{[0.6]}{[0.2]}]^{x}$

$3 = 3^{x} \\\\x =1$

Order w.r.t B : Use trials 2 and 5

$\frac{Rate2}{Rate5}= [\frac{[B(2)]}{[B(5)]}]^{y}$

$\frac{80}{20}= [\frac{[0.4]}{[0.2]}]^{y}$

$4 = 2^{y} \\\\y =2$

Order w.r.t C : Use trials 1 and 2

$\frac{Rate1}{Rate2}= [\frac{[A(1)]}{[A(2)]}]^{x}[\frac{[B(1)]}{[B(2)]}]^{y}[\frac{[C(1)]}{[C(2)]}]^{z}$

we know that x = 1 and y = 2, substituting the appropriate values in the above equation gives:

$\frac{160}{80}= [\frac{[0.4]}{[0.2]}]^{1}[\frac{[0.4]}{[0.4]}]^{2}[\frac{[0.2]}{[0.4]}]^{z}$

$1 = (0.5)^{z}$

z = 1

Therefore, order w.r.t C = 1

8 0

4 years ago

radioisotope actinium 225 has half life of 10 days, I begin with 16 kg of this isotope, how much will remain after 40 days?

Igoryamba

$N(t)=N_{0}(\frac{1}{2})^\frac{t}{\tau_{_\frac{1}{2}}}}\\\\
N_{0}=16kg\\
t=40days\\
\tau_{_\frac{1}{2}}}=10days\\\\\\
N(t)=16kg*(\frac{1}{2})^{\frac{40}{10}}=16kg*\frac{1}{16}=1kg$

3 0

3 years ago