Atoms of arsenic (As) are often added to silicon (Si) in a process called doping to change the conductivity of the silicon. How does the addition of arsenic change the conductivity of silicon?


a) An atom of arsenic has one fewer valence electron and more electron shells than an atom of silicon, so the conductivity decreases because the arsenic atom gains an electron.

b) An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity decreases because the arsenic atom loses the electron.

c) An atom of arsenic has one fewer valence electron and fewer electron shells than an atom of silicon, so the conductivity increases because the arsenic atom gains an electron.

d) An atom of arsenic has one more valence electron and more electron shells than an atom of silicon, so the conductivity increases because the arsenic atom loses the electron.


HAD TO POST THIS THIS BC THE OTHER POSTED IS WRONG

Answer:

Large crystals

Slowly

Explanation:

Recrystallization is a procedure used to purify an impure compound in a solvent. The concept used here is that the solubility of most of the solids increases with increase in temperature.

Recrystallization is also called as method of fractional crystallization.

After a recrystallization, a pure substance will ideally appear as a network of large crystals. If this is not the case, it may be worthwhile to reheat the flask and allow the contents to cool more slowly.

Answer:

C) tellurium (Te) is the correct answer.

Answer:

Distance between C-C in ethane- 1.54 Å

Distance between H atoms in eclipsed conformation-2.3 Å

Distance between H atoms in staggered conformation- 2.5 Å

Staggered conformation is more stable

Explanation:

The staggered conformation of ethane can be demonstrated as the most stable of conformation of ethane, because the angles between Carbon-Hydrogen bonds in both the front and back carbon atoms are maximized.  This now minimizes the energy of this conformation compared to the eclipsed conformation.

Considering the eclipsed conformation, it is obvious that the electron densities on Carbon-Hydrogen bonds come very close together thereby bringing two C-H bonds  into a dihedral angle of almost zero degrees. This causes their electron clouds to experience strong repulsion, thereby raising the molecules's total energy.

Answer:2NaF + Br2 —> 2NaBr + F2

2K + Cl2 —> 2KCl

N2+ 3F2 —> 2NF3

Explanation:

Answer:

7.93 × 10⁻¹³ km/s

Explanation:

Step 1: Given data

Rate of growth of the fingernails (r): 2.50 cm/year

Step 2: Convert "r" from cm/year to km/year

We will use the following conversion factors.

[tex]\frac{2.50cm}{year} \times \frac{1m}{100cm} \times \frac{1km}{1000m} = 2.50 \times 10^{-5} km/year[/tex]

Step 3: Convert "r" from km/year to km/s

We will use the following conversion factors.

[tex]\frac{2.50 \times 10^{-5} km}{year} \times \frac{1year}{365day} \times \frac{1day}{24h} \times \frac{1h}{60min} \times \frac{1min}{60s} = 7.93 \times 10^{-13} km/s[/tex]

2.50 cm/year is equal to 7.93 × 10⁻¹³ kilometers/second.

Answer:

endothermic reaction

Explanation:

When Elsa from Frozen freezes things, it is an example of an endothermic chemical reaction.

An endothermic involves a reaction in which heat is absorbed from the surrounding. Hence the surrounding becomes colder at the end of the the change.

So, Elsa draws heat from the environment and this causes the environment to be colder and things that are in contact with her.

Mass of sample : 1987.5 g≈1990 g

Given

12% mass of Lithium chlorate

Required

Mass of sample

Solution

%mass = (mass of solute/mass of solution) x 100%

mass of solute = mass of Lithium chlorate = 238.5 g

Input the value :

12/100(0.12) = 238.5 g : mass of solution

mass of solution =238.5 : 0.12

mass of solution = 1987.5≈1990 g

x = = 0.50 M Answer:

In order to produce some SbCl5, a 1.00 mole sample of SbCl3 is first placed in an empty 2.00 liter container maintained at a temperature different from 182oC. At this temperature, Kc, equals 0.117. How many moles of Cl2 must be added to this container to reduce the number of moles of SbCl3 to 0.700 mole at equilibrium

Moles Cl2 that must be added = 0.40 mol

Explanation:

K = ( = 0.117

Equilibrium concentrations:

= (1.00 - 0.70) mol / 2.00 L = 0.15 M <<---why is it 1.00-0.70???

= 0.700 mole / 2.00L = 0.350 M

= x

Kc = ÷ (0.15) = 0.117

Moles Cl2 at equilibrium = 0.050 mol L x 2.00 L = 0.10 mol

Moles Cl2 needed to make 0.300 mol SbCl3 into SbCl5 = 0.30 mol

Moles Cl2 that must be added = 0.40 mol

Answer:

4Al+3O2→2Al2O3

Explanation:

Answer:

0.171 M

Explanation:

Step 1: Given data

Step 2: Calculate the moles of solute

The molar mass of H₃PO₄ is 97.99 g/mol.

3.35 g × 1 mol/97.99 g = 0.0342 mol

Step 3: Convert "V" to liters

We will use the conversion factor 1 L = 1000 mL.

200 mL × 1 L/1000 mL = 0.200 L

Step 4: Calculate the molarity of the solution

We will use the definition of molarity.

M = moles of solute / liters of solution

M = 0.0342 mol/0.200 L = 0.171 M

Answer:

20g or 0.2kg

Explanation:

this is because the mass of the powder is 20g and this will be added to the original mass of the milk causing it to increase by that amount

Answer: 20g

Explanation:

Answer:

I would pipet 4 μl of each BSA work solution

Explanation:

To calculate the mass (in μg), we have to multiply the concentration C (in μg/ul) by the volume V (in μl):

C(μg/ul) x V( μl) = mass (μg)

We found the required volume for each solution, as follows:

5 μg/μl x V₁ = 20 μg ⇒ V₁ = 20 μg/(5 μg/μl ) = 4 μl

0.5 μg/μl x V₂ = 2 μg ⇒ V₂ = 2 μg/(0.5 μg/μl) = 4 μl

0.05 μg/μl x V₃ = 0.2 μg ⇒ V₃= 0.2 μg/(0.05 μg/μl) = 4 μl

Therefore, we need to pipet 4 μl of the solutions of concentrations 5μg/μl, 0.5 μg/μl, and 0.05 μg/μl to obtain the masses 20 μg, 2 μg, and 0.2 μg, respectively.

Answer:

d. 9.95 × 10⁻³ mol

e. 249 g

f. 2.55 × 10²⁴ atoms

g. 4.32 × 10²² atoms

Explanation:

d. the number of moles of cobalt represented by 5.99 x 10²¹ cobalt atoms

We will use Avogadro's number: there are 6.02 × 10²³ atoms of cobalt in 1 mole of atoms of cobalt.

5.99 x 10²¹ atoms × 1 mol/6.02 × 10²³ atoms = 9.95 × 10⁻³ mol

e. the mass of 4.23 mol of cobalt

The molar mass of cobalt is 58.93 g/mol.

4.23 mol × 58.93 g/mol = 249 g

f. the number of cobalt atoms in 4.23 mol of cobalt

We will use Avogadro's number: there are 6.02 × 10²³ atoms of cobalt in 1 mole of atoms of cobalt.

4.23 mol × 6.02 × 10²³ atoms/1 mol = 2.55 × 10²⁴ atoms

g. the number of cobalt atoms in 4.23 g of cobalt

First, we will calculate the moles of cobalt using the molar mass of cobalt.

4.23 g × 1 mol/58.93 g = 0.0718 mol

Then, we will calculate the number of cobalt atoms using Avogadro's number.

0.0718 mol × 6.02 × 10²³ atoms/1 mol = 4.32 × 10²² atoms

Answer:

Egypt

Explanation:

Hi again

Answer:

An ecosystem is a community or group of living organisms that live in and interact with each other in a specific environment.

Explanation:

That's the most straight forward explanation I could come up with

Answer:

b

Explanation:

Answer:

Incorrect

Explanation:

Mole ratios are derived from the coefficients in front of the number, N2O does not have a 2 in front of it, the real mole ratio would be 4/1

Answer:

Correct

Explanation:

I had the same problem and I put correct, and it was correct.

Answer:

Weather is at a specific place and time. Climate is over a period of time.

Explanation:

That is the difference

Answer:

A) Mass = 32 g of KCl

Explanation:

Given data:

Mass of potassium chloride produced = ?

Mass of potassium chlorate = 52 g

Solution:

Chemical equation:

2KClO₃     →       2KCl + 3O₂

Number of moles of KClO₃:

Number of moles = mass/molar mass

Number of moles = 52 g/ 122.55 g/mol

Number of moles = 0.424 mol

Now we will compare the moles of KClO₃ and KCl

             KClO₃      :       KCl

               2            :       2

          0.424         :       0.424

Mass of KCl:

Mass = number of moles × molar mass

Mass = 0.424 mol × 74.55 g/mol

Mass = 32 g

Answer:

h3po2

Explanation:

Answer:

i think it is H3PO4

Explanation:

Answer:

d. 10 million years

Explanation:

These are the options for the question

Choose one answer.

a. 2.5 million years

b. 5 million years

c. 15 million years

d. 10 million years

✓half-life of the radioactive substance= 5 million years

✓ Then for every 5 million years, original radioactive given (100%) percentage is reduced by factor of 1/2.

✓ 1st 5 million year; After the first 5 million years, the original radioactive is reduced as;

(100%) × 1/2 = 50% remains

✓2nd 5 million year: At 10 millions year, the 50% remaining radioactive is reduced by factor of 1/2

(50%) × 1/2 = 25% remains

Hence, at At 10 millions years 25% of the original radioactive atoms remain

.

Answer:

10 million years

Answer:

0.864 g/mL.

Explanation:

I hope this helps u! also have a great rest of your day!

Answer:

ANSWER OS HERE

Explanation:

THE O2- has two more extra electrons due to presence of 2 negative charges so a total of 10 electrons and the element that has 10 electrons in the periodic table in its neutral state is Neon (Ne) ( atomic number (10) = no.of protons = no. of electrons) so neutral element with same electron configuration as O2- is Ne. Log in or register to post comments.

The electron configuration of the neutral atom is an useful place to start when trying to determine the electron configuration of an ion.

The neutral atom in your situation is sulfur (S), which is found in group 16 of period 3 of the periodic chart. A neutral sulfur atom has a total of 16 electrons surrounding its nucleus since sulfur has an atomic number of 16. Thus, a neutral sulfur atom will have the following electron configuration. Now, a neutral sulfur atom receives two more electrons to create the sulfide anion, or S2. These two electrons will be added to the 3p-orbitals, which can hold a maximum of two protons, as you can see in the configuration of the neutral atom. between them, a maximum of six electrons. Thus, the sulfide anion's electron configuration will be the electron configuration of neon, the noble gas that appears before sulfur in the periodic table, will be used in the shorthand notation for noble gases for the sulfide anion.

To know more about Electronic configuration, visit-https://brainly.com/question/13497372

#SPJ2

Answer:

Percent relative error = 0.191%

Explanation:

Relative error is a measure of accuracy (How closeness is the measure to the accepted value) for a determined data. The formula is:

Percent relative error = |Experimental - Accepted| / Accepted * 100

Where experimental is the average of the data:

(40.220g/mol + 40.654g/mol + 40.314g/mol + 40.165g/mol + 40.554g/mol) / 5 =

40.381g/mol

Replacing using accepted value = 40.304g/mol:

|40.381g/mol - 40.304g/mol| / 40.304g/mol * 100

Answer:

Answer:

Reversible

Explanation:

Changes of state are physical changes in matter. Common changes of the state include melting, freezing, sublimation, deposition, condensation, and vaporization.

Answer:

A is the answer the reason why is because I got it right when I was doing my test

Answer:

24.9%

Explanation:

According to this question, mole fraction of NaCl in an aqueous solution is 0.0927. This means that the mole percent of NaCl in the solution is:

0.0927 × 100 = 9.27%

Let's assume that the solution contains water (solvent) + NaCl (solute), hence, the mole fraction of water will be;

100% - 9.27% = 90.73%

THEREFORE, it can be said that, NaCl contains 0.0927moles while H2O contains 9.073moles

N.B: mole = mass/molar mass

Given the Molar Mass

NaCl: 58.44 g/mol

H2O: 18.016 g/mol

For NaCl;

0.0927 = mass/58.44

mass = 0.0927 × 58.44

5.42g

For H2O;

9.073 = mass/18.016

mass = 9.073 × 18.016

= 16.35g

Total mass of solution = 16.35g + 5.42g = 21.77g

Mass percent of NaCl = mass of NaCl/total mass × 100

% mass of NaCl = 5.42g/21.77g × 100

= 0.249 × 100

= 24.9%

Answer:

24.9

Explanation:

Answer:

Explanation:

The aim of this question is to draw the structure of genistein and determine the number of atoms with sp² hybridization in the molecule.

From the image below, we will see the lewis structure of genistein. From the image, the blue asterisk atoms are sp² hybridized and the red marked atoms are sp³ hybridized.

We will also notice that all the carbon atoms contain 3 σ-bonds with no lone pair of electrons.

Using the knowledge of Valence shell electron repulsion theory (VSEPR), the above-mentioned carbon atom is said to be sp²hybridized.

Also, the oxygen atoms which are doubly bounded contains 1 σ-bond and 2 lone pair electrons. These oxygen atoms are also sp² hybridized.

Finally, the singly bonded oxygen atom is composed of 2 σ-bonds and 2 lone pair electrons. This makes it to be sp³ hybridized.

Altogether, we have a total of 16 sp² hybridized atoms and 4 sp³ hybridized atoms.

The ocean is not a part of Earth's layers.

Answer:

Ocean

Explanation:

Answer:

1.51×10²³ atoms.

Explanation:

From the question given above, the following data were obtained:

Mass of Calcium (Ca = 10 g

Number of atom of Calcium (Ca) =?

The number of atoms present in 10 g of Ca be obtained as follow:

From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms. This implies that 1 mole Ca contains 6.02×10²³ atoms.

1 mole of Ca = 40 g.

Now, if 40 g of Ca contains 6.02×10²³ atoms.

Therefore, 10 g of Ca will contain = (10 × 6.02×10²³) / 40 = 1.51×10²³ atoms.

Thus, 10 g of calcium contains 1.51×10²³ atoms.