how does the number of valence electrons change as you move to the right across the periodic table?

Answer:

A stock or standard solution is a solution in which you accurately know its concentration. You can make stock solutions in the chemistry laboratory or buy from chemical manufacturers. Once you have a stock solution, you can prepare solutions of lower concentration by diluting the concentrated stock solution.

Explanation:

To make the correct volume of stock solution, we should add first solid to a volumetric flask.

Stock solution is a standard solution in which exact concentration of solute is present in particular volume. It is mainly used in analytical chemistry during the titration process.

During the preparation of stock solution, we should first add solid in the volumetric flask and then little amount of water to dissolve the solid and then finally add water to the required volume. If we first add total volume and then add solid then dissolution of solid may increase volume.

Hence, first we add solid in the volumetric flask.

To know more about stock solution, visit the below link:

https://brainly.com/question/3942978

ฮH=+ ฮ๐=+ (Endothermic and expansion)

In this phase change, heat is absorbed by the system, and the volume of the system increases.

ฮH=+ ฮ๐=โ (Endothermic and compression)

In this phase change, heat is absorbed by the system, but the volume of the system decreases.

ฮH=โ ฮ๐=+ (Exothermic and expansion)

In this phase change, heat is released by the system, and the volume of the system increases.

ฮH=โ ฮ๐=โ (Exothermic and compression)

In this phase change, heat is released by the system, but the volume of the system decreases.

To know more about (Endothermic and expansion) click this link -

brainly.com/question/31214950

#SPJ11

The concentrations of BSA in the 1:10 and 1:20 dilution cuvettes are 10 mg/mL and 20 mg/mL, respectively. The concentration of the stock BSA solution is 15.32 µg/mL.

To calculate the bsa concentration in the 1:10 and 1:20 dilution cuvettes, we need to use the dilution equation:
C1V1 = C2V2
For the 1:10 dilution cuvette, we know that the dilution factor is 1/10, so V2 is 1/10 of the initial volume. Let's call the initial volume of the stock solution V0. Then, we have:
C1V0 = C2(V0/10)
C2 = (C1V0)/(V0/10) = 10C1
So, the concentration of BSA in the 1:10 dilution cuvette is 10 times less than the stock solution. Therefore, the concentration of BSA in the 1:10 dilution cuvette is:
C2 = 10 x 1 mg/mL = 10 mg/mL
For the 1:20 dilution cuvette, we use the same equation but with a dilution factor of 1/20:
C1V0 = C2(V0/20)
C2 = (C1V0)/(V0/20) = 20C1
So, the concentration of BSA in the 1:20 dilution cuvette is 20 times less than the stock solution. Therefore, the concentration of BSA in the 1:20 dilution cuvette is:
C2 = 20 x 1 mg/mL = 20 mg/mL
Now, to calculate the concentration of the stock solution, we can use the Beer-Lambert law, which relates the absorbance (A) of a solution to its concentration (C) and the path length (l) of the cuvette:
A = εcl
C = 0.667/(43,500 M^-1 cm^-1 x 1 cm) = 0.00001532 M = 0.01532 mg/mL

To know more about dilution visit :-

https://brainly.com/question/28997625

#SPJ11

Assuming the sun's energy is radiated uniformly in all directions,  the total power is (π \(r . ^{2}\) * σ\(R^{2} T^{4}\))/\(r^{2}\)

According to Stefan's law, if the sun were a perfect blackbody, its energy output per second would be:

P=σA\(T^{4\left \ }\)

(Where P is energy radiated per second and A is the area of the sun.)

⇒P=σ×4π\(R^{2} T^{4}\).............(1)

Assuming r>>r., the strength of this power at the earth's surface is

I= P/4π\(r^{2}\)

​⇒I= σ×4π\(R^{2} T^{4}\)/4π\(r^{2}\)

(Inserting the value obtained from equation (1))

⇒I= σ\(R^{2} T^{2}\)/\(r^{2}\)

Due to its great distance from the sun, the earth only receives a small portion of the energy that is radiated. The earth can be visualized as a little disc with a radius equal to that of the planet.

The disc's surface area is \(r .^{2}\) hence the earth's total radiant energy as received is:

PE=π\(r. ^{2}\)×I

P E = (π \(r . ^{2}\) * σ\(R^{2} T^{4}\))/\(r^{2}\)

Assuming the sun's energy is radiated uniformly in all directions,  the total power is (π \(r . ^{2}\) * σ\(R^{2} T^{4}\))/\(r^{2}\)

Learn more about the sun's energy here:-

https://brainly.com/question/1140127

#SPJ4

If the initial concentration of base b in solution is 0.18 m. if the pH of the solution at equilibrium is 13.190, the percent ionization of the base is 78.3.

Calculating the concentration of hydroxide ions (OH⁻) in the solution at equilibrium is necessary to ascertain the base's percent ionization.

It is observed that the solution is basic, so use the following relationship:

pOH + pH = 14

According to question, the pH at equilibrium is 13.190, so find the pOH:

pOH = 14 - 13.190

= 0.810

Now, change pOH to [OH⁻] concentration:

[OH⁻] = \(10^_(-pOH)}\)

= \(10^{-0.810}\)

= 0.141 M

The concentration of [OH⁻] at equilibrium is 0.141 M.

To find the percent ionization of the base, it is required to compare the concentration of [OH⁻] at equilibrium with the initial concentration of the base.

Percent ionization = ([OH] / [B]) × 100

Place the values, it is observed that:

Percent ionization = (0.141 M / 0.180 M) × 100

= 78.3

The base has a 78 percent ionization rate, rounded to the closest whole number.

Thus, the base has a 78 percent ionization rate, rounded to the closest whole number.

Learn more about percent ionization, here:

https://brainly.com/question/30060037

#SPJ6

Answer: I put 78 on my homework and got it wrong. The computer said it was 86%

Explanation:he percent ionization is the ratio of the hydroxide ion concentration at equilibrium to the initial concentration of the base, multiplied by 100. Based on the pH, the equilibrium concentration of hydroxide ions is

[OH−]=10−(14.000−pH)=10−0.810=0.155

Therefore, the percent ionization is

0.155 M0.18 M×100=86%

A maximum of two electrons will be placed in 1s first. With a maximum of two electrons, 2s will then be filled. With a maximum of 6 electrons, 2p will then be filled.

To learn more about orbital refer to:

https://brainly.com/question/20319149

#SPJ1

After adding sodium bicarbonate (NaHCO₃) to a mixture, you can observe the separation of the layers based on their variations in density and solubility to ascertain which layer is the aqueous layer.

NaHCO₃ is water-soluble, so when it is added to a mixture, it will dissolve in the aqueous layer, if present. The organic layer, on the other hand, typically consists of organic solvents that are immiscible with water.

Here's a general procedure to determine the aqueous layer:

1. After adding NaHCO₃ to the mixture, gently shake or swirl the mixture to allow for thorough mixing.

2. Allow the mixture to sit undisturbed for a short period to allow phase separation to occur. The layers will separate based on their densities, with the denser layer settling at the bottom.

3. Observe the separation of the layers. The layer that appears at the bottom is likely the aqueous layer containing the dissolved NaHCO₃.

4. Carefully transfer the bottom layer (aqueous layer) to a separate container using a suitable separation technique such as pipetting or pouring.

5. The remaining layer, usually on top, is the organic layer, which can be collected separately if needed.

It's important to note that the specific characteristics of the mixture and the solvents used will influence the separation process. Adjustments may be required based on the particular experimental setup and the properties of the compounds involved.

To know more about the sodium bicarbonate refer here :

https://brainly.com/question/29238400#

#SPJ11

Answer:

The atoms present at the beginning of the reaction is equal to the atoms present at the end of the reaction. This is because matter can neither be created nor be destroyed in an ordinary chemical reaction.

Explanation:

During photosynthesis, 6 molecules of water react with 6 molecules of carbon dioxide to form 1 molecule of glucose and 6 molecules of oxygen. The equation for the photosynthesis reaction is

6CO2 + 6H2O --> C6H12O6 + 6O2

At the beginning of the reaction, there is 6 carbon atoms, 18 oxygen atoms and 12 hydrogen atoms while at the end of the reaction, there is 6 carbon atoms, 12 hydrogen atoms and 18 oxygen atoms.  This is because according to the law of conservation of mass and matter, it can neither be created nor be destroyed in an ordinary chemical reaction. The number of atoms present at the beginning of the reaction must be equal to the number of atoms present at the end of the reaction.

Answer:

2.78%

Explanation:

Answer:

0.225M

Explanation:

Equation: M=n/v

n = moles of solute

v = liters of solution

NaCl = 58.443 g/mol

16.88/58.443= 0.289 moles of NaCl

0.289/1.283=0.225M

To reach the equivalence point in a 16.3 ml aliquot of triprotic acid 48.9 ml of 0.1 M potassium hydroxide is needed.

An aliquot is a portion of a sample that is taken for the analysis or testing . It is also defined as the sub measured volume of the original sample.

To calculate the volume of potassium hydroxide needed to reach the equivalence point in a 16.3 ml aliquot of triprotic acid, we need to know the concentration of the potassium hydroxide solution and the molarity of the triprotic acid.

Assuming that the triprotic acid is fully ionized and that the potassium hydroxide is a strong base, we can use the following balanced chemical equation:

\(\rm 3 HX + KOH \rightarrow KX + 3 H_2O\)

where HX is the triprotic acid and KX is the potassium salt of the acid.

At the equivalence point, the moles of acid and base are equal, so we can use the following equation to calculate the volume of potassium hydroxide needed:

moles of acid = moles of base

Molarity of acid × volume of acid = Molarity of base × volume of base

Since, the triprotic acid has three acidic protons, its molarity is three times the concentration of the 16.3 ml aliquot.

Let's assume that the concentration of the aliquot is 0.1 M, then the molarity of the triprotic acid is 0.3 M.

Let's also assume that the concentration of the potassium hydroxide solution is 0.1 M.

Using the equation above, we can solve for the volume of potassium hydroxide needed:

0.3 M × 16.3 ml = 0.1 M × volume of potassium hydroxide

volume of potassium hydroxide = 48.9 ml

Therefore, it would take 48.9 ml of 0.1 M potassium hydroxide to reach the equivalence point in a 16.3 ml aliquot of 0.3 M triprotic acid.

Learn more about aliquot here:

https://brainly.com/question/31440822

#SPJ4

Since the actual value of the atomic radius of platinum  atoms was not given in the problem, I chose 175 pm which gives an error of 18.28%.

The actual atomic radius of platinum atoms is 175 pm

We can see from the question that the measured value of the  atomic radius of platinum  atoms was determined to be 143 pm.

Recall that;

Percent error = Absolute value of (measured value - actual value)/actual value * 100

Since the actual value of the atomic radius was not given, let us take it to be 175 pm for the purpose of this problem

Percent error = Absolute value of (143 - 175)/175 * 100

Percent error = 18.28%

Learn more: https://brainly.com/question/4170313

The percent error of this measured value ; ( D ) approximately 13%

The percent error of a measured value

= [ ( actual value - measured value ) / ( actual value ) ]  * 100

= [ ( 175 pm - 143 pm ) / ( 175 pm ) ]  * 100

=  18.29%

From the options given the closest value to the calculated value is 13%

Hence we can conclude that the percent error of this measured value is approximately 13%.

Learn more : https://brainly.com/question/2138898

Although some data related to the question is missing the actual value of the atomic radius of platinum is 175 pm

Option (d), P=ATC=MR=MC, accurately represents the long-run equilibrium condition for perfect competition, reflecting the balance between price and cost for firms operating in a competitive market.

The long-run equilibrium condition for perfect competition is that price (P) is equal to average total cost (ATC), which is also equal to marginal cost (MC), and marginal revenue (MR).

Option (d), P=ATC=MR=MC, best represents the long-run equilibrium condition for perfect competition. In perfect competition, firms operate at the minimum point of their average total cost curve, where price equals both average total cost and marginal cost. This condition ensures that firms are earning zero economic profit and are producing at an efficient level.

In the long run, if firms are earning economic profit, new firms will enter the market, increasing competition and driving prices down. Conversely, if firms are experiencing losses, some firms may exit the market, reducing competition and causing prices to rise. This process continues until firms reach a state where price equals average total cost, marginal cost, and marginal revenue, ensuring a long-run equilibrium.

Therefore, option (d), P=ATC=MR=MC, accurately represents the long-run equilibrium condition for perfect competition, reflecting the balance between price and cost for firms operating in a competitive market.

Know more about Equilibrium here:

https://brainly.com/question/30694482

#SPJ11

Answer:

because they take thousands or even millions of years to naturally replenish or replaced , which is not the average human lifetime

The balanced equation is

2Al + 3H2 ---> 2AlH3

Answer:

2

Explanation:

Answer:

2

Explanation:

Answer:

Moving the balls closer together. The distance decreases and force increases.

The maximum possible efficiency for such an engine is 6.039 %.

Temperature of water near the surface of a tropical ocean = 298.2 K

Temperature of water 700 m beneath the surface = 280.2 K

To find the maximum possible efficiency for the given heat engine,

The maximum possible efficiency of a heat engine depends only on the temperatures of the hot and cold reservoirs, and is given by Carnot efficiency,  η = (T₁ - T₂)/T₁

whereT₁ is the temperature of hot reservoir, T₂ is the temperature of cold reservoir. Temperature is given in Kelvin.

The temperature difference between the hot and cold reservoirs is, T₁ - T₂ = 298.2 K - 280.2 K = 18 K

Substitute these values in the Carnot efficiency equation,

Carnot efficiency, η = (T₁ - T₂)/T₁ = (18 K)/298.2 K = 0.06039. The maximum possible efficiency for such an engine is 6.039 %.

Generalised function is given as η = (T₁ - T₂)/T₁

Learn more about efficiency of Carnot engine: https://brainly.com/question/27359482

#SPJ11

One disadvantage of Hopfield neural networks is that their structure can be challenging to replicate on an electronic circuit board due to their complex connections and recurrent architecture.

One of the main disadvantages of Hopfield neural networks is their inability to be easily implemented on an electronic circuit board. This is due to their complex structure, which involves a large number of interconnected neurons and synapses. Unlike simpler neural networks, such as feedforward networks,

Hopfield networks require a significant amount of hardware and memory resources to be implemented in an electronic circuit board. This makes them less suitable for applications where size and power consumption are critical factors, such as mobile devices or embedded systems.

Additionally, the complexity of Hopfield networks makes them harder to train and optimize compared to other types of neural networks, which can limit their effectiveness in certain applications. This limitation may restrict their practical applications in hardware-based implementations.

To learn more about complex structure click here

brainly.com/question/30490006

#SPJ11

In the above intermediate chemical equation, oxygen will appear as follows: O₂(g) as a reactant (option B).

A chemical equation in chemistry is a symbolic representation of a chemical reaction where reactants are represented on the left, and products on the right.

According to this question, an intermediate chemical equation is presented as follows:

As observed in the above chemical equation, oxygen will react in its gaseous form i.e. as a reactant.

Learn more about chemical equation at: https://brainly.com/question/28294176

#SPJ1

Answer: 4 FeSO4(s) + O2(g) + 10 H2O(l) ---> 4 Fe(OH)3 + 4 H2SO4

Explanation:

FeSO4(s) + O2(g) + H2O(l) = Fe(OH)3 + H2SO4

In other to balance the equation, the total number of atoms of each element on the Left Hand Side (LHS) of the equation must be equal to the total number of atoms on the  Right Hand Side (RHS) of the equation.

Add the following coefficients to the equation;

FeSO4 = Add 4,  H20 = Add 10,  Fe (OH)3 = Add 4 and H2SO4 = Add 4

By doing this, you will discover that the total number of atoms on bothe sides of the equation are balanced; thus we have;

4 FeSO4(s) + O2(g) + 10 H2O(l) ---> 4 Fe(OH)3 + 4 H2SO4

Answer:

They are both letters?

Explanation:

150 mL of 0.100 M NaOH is needed to completely neutralize 50.0 mL of 0.300 M HCl. To determine the amount of NaOH needed to neutralize the HCl, we must first balance the chemical equation. HCl + NaOH → NaCl + H2O. The balanced equation tells us that one mole of NaOH reacts with one mole of HCl.

We can use the formula M1V1 = M2V2 to calculate the amount of NaOH needed. First, we determine the number of moles of HCl present in 50.0 mL of 0.300 M HCl:

0.300 mol/L x 0.0500 L = 0.0150 moles HCl

Since one mole of NaOH is needed to neutralize one mole of HCl, we need 0.0150 moles of NaOH.

Now, we can use the concentration of the NaOH solution to calculate the volume needed:

0.100 mol/L x V = 0.0150 moles

V = 0.0150 moles / 0.100 mol/L = 0.150 L = 150 mL

Therefore, 150 mL of 0.100 M NaOH is needed to completely neutralize 50.0 mL of 0.300 M HCl.

To know about neutralize :

https://brainly.com/question/14156911

#SPJ11

Answer:

0.15

Explanation:

The equilibrium constant expression for the given reaction is:

Kc = ([C₂H₂][H₂]³)/[CH₄]²

Substituting the given equilibrium concentrations, we get:

Kc = [(0.035 M)(0.115 M)²]/(0.035 M)³

Simplifying, we get:

Kc = 0.15

Therefore, the value of Kc for the reaction is 0.15, rounded to 2 significant figures.

Explanation:

n=,4.5 moles C2H6

the ratio 2:7

4.5:x

x=15.75 moles

Answer:

Its B :)

Hope this helps

Image B will shows the butter particles before and after thermal energy will be transferred to the solid butter by heating. So, the correct option is B.

The energy present in a system that determines its temperature is referred to as thermal energy. Thermal energy flows as heat. Thermodynamics is a whole field of physics that studies how heat is transmitted across various systems and how work is performed in the process.

The butter particles in Picture B are shown both before and after the solid butter has been heated to transmit thermal energy to it. This image shows a solid butter particle with tightly packed molecules, however when the butter is heated, it melts into a liquid form with loosely packed molecules.

Thus, the correct option is B.

Learn more about Thermal energy, here:

https://brainly.com/question/11278589

#SPJ3

Answer:N-1

             H-3

             C-1

             H-4

Explanation:Nitrogen-1,Hydrogen-3(Ammonia),Carbon-1,Hydrogen-4(Methane).

the use of NaOH solution in extraction procedures can help to adjust the pH of the solution, enhance the solubility of organic compounds in the aqueous layer, and help to separate different compounds based on their relative solubilities.

NaOH (sodium hydroxide) solution is often used in extraction procedures to adjust the pH of the solution and to make the organic compounds more soluble in the aqueous layer.

When an organic compound is mixed with water, it may dissolve partially or not at all due to differences in polarity between the two substances. By adjusting the pH of the solution with NaOH, the organic compounds can become more soluble in the aqueous layer because the addition of a basic solution can convert acidic functional groups in the organic compound to their conjugate bases. For example, carboxylic acids (an acidic functional group commonly found in organic compounds) can be converted to their water-soluble carboxylate salt forms by the addition of a basic solution such as NaOH.

Learn more about ph here:

https://brainly.com/question/26856926

#SPJ4