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explaining

Answer:

The H—C—H bond angle in methane is the tetrahedral angle, 109.5°. This angle is obtained when all four pairs of outer electrons repel each other equally. The bond angles in ammonia and in water are less than 109.5° because of the stronger repulsion by their lone pairs of electrons.

Explanation:

hope it helps!

Answer:

I⁻ , Sr²⁺ , K⁺

Explanation:

refer to the periodic table and memorize trends in charges.

The correct decay series :

₈₄Po²¹⁴⇒₈₃Bi²¹⁰+₂He⁴+ ₋₁e⁰+ ₀γ⁰

Radioactivity is the process of unstable isotopes to stable isotopes by decay, by emitting certain particles,  

Decay's reaction :

₈₄Po²¹⁴⇒₈₃Bi²¹⁰+x+y+z

From this decay reaction can be concluded

mass number decreased by 4

atomic number decreased by 1

Then the most suitable are:

Polonium-214 undergoes 1 alpha decay 1 beta decay and 1 gamma emission.

₈₄Po²¹⁴⇒₈₃Bi²¹⁰+₂He⁴+ ₋₁e⁰+ ₀γ⁰

So that the mass number and atomic number are the same both before and after decay

Answer:

P₂ = 299.11 KPa

Explanation:

Given data:

Initial volume = 600 mL

Initial pressure = 70.00 KPa

Initial temperature = 20 °C (20 +273 = 293 K)

Final temperature = 40°C (40+273 = 313 K)

Final volume = 150.0 mL

Final pressure = ?

Formula:  

P₁V₁/T₁ = P₂V₂/T₂  

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Solution:

P₂ = P₁V₁ T₂/ T₁ V₂  

P₂ =  70 KPa × 600 mL × 313 K / 293K ×150 mL  

P₂ = 13146000 KPa .mL. K /43950 K.mL

P₂ = 299.11 KPa

Answer:

no

Explanation:

Answer:

yes its what the other person said

Explanation:

Answer:

3.22  * 10^-4 M

Explanation:

The cell reaction equation is;

2Al(s) + 3Cu^2+(aq) ------> 2Al^3+(aq) + 3Cu(s)

E° = 0.337 V - (-1.66 V)

E° = 1.997 V

Given that the cell potential is 2.067 V, from Nernst's equation;

E = E° - 0.0592/n log Q

Substituting values;

2.067 = 1.997 - 0.0592/6 log [Al^3+]^2/[1.07]^3

0.07 = - 0.0592/6 log [Al^3+]^2/[1.07]^3

- 7.07 = log [Al^3+]^2/[1.07]^3

Antilog (- 7.07) =  [Al^3+]^2/[1.07] ^3

8.5 * 10^-8 =  [Al^3+]^2/[1.07]^3

[Al^3+]^2 = 8.5 * 10^8  * 1.07 ^3

[Al^3+]^2 = 1.04 * 10^-7

[Al^3+] = √1.04 * 10^-7

[Al^3+] = 3.22  * 10^-4 M

Answer:

D

Explanation:

D

Answer:

7.8%

Explanation:

Given that:

The initial mass amount of aspirin = 0.020g

The standard molar mass of aspirin = 240 g/mol

Thus, the number of moles = mass/molar mass

= 0.020/240

= 0.0000833 moles

Now, the molarity of aspirin in the solution(diluted) [tex]C_1[/tex] = [tex]\dfrac{8.33 \times 10^{-5}}{0.01}[/tex]

= [tex]= 8.33 \times 10^{-3} \ M[/tex] (provided the volume v = 0.01 L)

The absorbance of the sample solution A =1.07

The path length (b) = 1 cm

From the standard value of salicylic acid, the coefficient (e)= 139.322 /M/cm

Now; according to Beer's law, the concentration of aspirin is:

A = e×b×c

[tex]c = \dfrac{A}{eb}[/tex]

[tex]c = \dfrac{1.07}{139.322 \times 1}[/tex]

c = 0.00768 M

Finally, relating the concentration of the aspirin, the percentage of salicylic acid the product  [tex]= \dfrac{0.00833-0.00768}{0.00833} \times 100[/tex]

= 7.8%

Periodic tables arrange and group the periodic element based on their similar properties and atomic number. Semiconductors are most likely to be found in columns IV and VI of the periodic table.

Semiconductors are solid substances defined by the property and ability to conduct the charge and heat. They show the property of conductivity and have been comprised mostly of metals. They are able to show conductivity due to electrical properties.

Semiconductors are mostly found in groups IV and VI of the periodic table; and comprises mainly of tin (Sn), silicon (Si),  tellurium (Te), germanium (Ge), and selenium (Se). These elements are used in transistors and diodes to conduct electricity.

The element is semiconductors only if they have more and fewer electrons in their outer valence shell of the atom so that they can be n or p-type semiconductors. They are majorly used in electronic devices.

Therefore, columns IV and VI of the periodic table are comprised of semiconductors.

Learn more about semiconductors, here:

https://brainly.com/question/18132856

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Answer:

F i think i pretty sure F!!!!!!!!

Answer:

p orbitals

Explanation:

Answer:

increases

Explanation:

Answer:

silicon or air or nickel or chocolate chip cookies i think

Explanation:

Answer:

The correct answer is a = 2 atm, b = 0.66 atm, and c = 1.66 atm.

Explanation:

a. When the temperature is constant, the ideal gas equation, that is, PV = nRT becomes PV = constant, or P1V1 = P2V2

Based on the given information, the pressure of the gas is 1.00 atm, the V1 of the gas is 78 ml, and the V2 of the gas is 39 ml.  

Now using the above formula we get,  

P2 = (P1V1) / (V2)

P2 = 1 atm * 78 ml/39 ml

P2 = 2 atm.  

b) Now the volume V1 is 43.5 ml, and the volume V2 is 65.5 ml at constant temperature, P1 is 1 atm. Now P2 will be,  

P2 = (P1V1) / (V2)

P2 = 1 atm * 43.5 ml/65.5 ml

P2 = 0.66 atm

c) In the given case, when the volume is decreased by 40 percent, let us consider that the volume, V1 be 100 ml, and the volume V2 be 60 ml, the P1 is 1 atm, now the P2 will be,  

P2 = (P1V1) / (V2)

P2 = 1 atm * 100 ml/60 ml

P2 = 1.66 atm.

Answer:

24.32 amu

Explanation:

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

Isotope A (Mg–24):

Mass of A = 24 amu

Abundance (A%) = 79%

Isotope B (Mg–25):

Mass of B = 25 amu

Abundance (B%) = 10%

Isotope C (Mg–26):

Mass of C = 26 amu

Abundance (C%) = 11%

Average atomic mass of Mg =?

Average atomic mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]

= [(24 × 79)/100] + [(25 × 10)/100] + [(26 × 11)/100]

= 18.96 + 2.5 + 2.86

= 24.32 amu

Thus, the average atomic mass of Mg is 24.32 amu

Answer:

C

Explanation:

the gray moths were able to hide better in the smoky air then cream colored moth and were able to stay alive.

Answer:

C

Explanation:

During the industrial revolution the grey moths could blend in more and have more camouflaged then the crème colored moths, that being said they had a better chance of reproduction and became more populated afterwards. hope this helps! :)

Answer:

[tex]189kJ[/tex]

Explanation:

Hello!

In this case, since one mole of ethanol release 8,842 J per 1 mole of ethanol, we can write:

[tex]\frac{8,842J}{1molC_2H_6H}[/tex]

Thus, since we need the energy released by 982.6 g of ethanol, we compute the moles in such mass of fuel:

[tex]n=982.6g\frac{1mol}{46.08g} =21.3mol[/tex]

Therefore, the result is:

[tex]\frac{8,842J}{1mol}*21.3mol=188,545J[/tex]

Which in kJ is:

[tex]189kJ[/tex]

Best regards!

Answer:

75.1

Explanation:

The isomers contains the similar and accurate chemical formulas but at the same time the structure of the molecular is different. This represents that the masses of the molecular would be similar

Therefore the molecular mass of methyl ethanoate, i.e. an isomer propanoic acid is 75.1 i.e. equivalent to the molecular mass of the propanoic acid

So, it should be 75.1

Answer:

8Ag2S 16Ag + S8

Explanation:

Answer: a burst

Explanation: a burst of energy could be substatuded for spark of energy

A spark of energy is required to begin the chemical reaction of burning a fossil fuel because; This spark of energy is required to attain the activation energy of the reaction.

Another name for this spark of energy is Ignition.

Definition:

The activation energy of a chemical reaction is the minimum amount of energy required for the commencement of the chemical reaction.

In this case, the spark of energy is required to attain the activation energy of the reaction.

Read more:

https://brainly.com/question/7639475

Answer:

False

Explanation:

humans have 23 pairs