define the term valency​

Answer:

It's basically an active site of an enzyme precisely fits a specific substrate. It reduces the energy that is well needed for reactants that come together.

The net ionic equation for the reaction between hydroiodic acid (HI) and ammonia (NH3) in aqueous solution:
HI(aq) + NH3(aq) → NH4+(aq) + I-(aq).

In this reaction, the hydroiodic acid donates a hydrogen ion (H+) to ammonia, which accepts the ion to form ammonium (NH4+). The iodide ion (I-) is a spectator ion and remains unchanged throughout the reaction. Therefore, it is not included in the net ionic equation. Spectator ions are typically found in reactions involving ionic compounds dissolved in water or in precipitation reactions. In these reactions, the ions present in the solution may undergo chemical changes while other ions remain unaffected.

To know more about Spectator ions, visit:

https://brainly.com/question/31200633

#SPJ11

The empirical formula for the compound if A denotes the cations and X denotes the anions is AX₂

It is given that the cations are denoted by Blue color and the anions with green color. There are 8 atoms in the corners and 6 in the face center. Then,

No of atoms in a total of all corners = 8 x 1/8

No of atoms in the corners = 1

No of atoms in the faces = 6 x 1/2

No of atoms in the faces = 3

Then,

Total no of cations atoms = total number of atoms in the corners + the total number of atoms in the faces

Total number of cations (A) = 1 + 3

Total number of cations (A) = 4

The total number of anions in the cell is 8 from the figures as they aren't shared with another lattice arrangement. Therefore,

Number of anions (X) = 8

Then the empirical formula would be A₄X₈ which could be written in the simplified form of AX₂.

Thus, the empirical formula is AX₂ for the arrangement.

To know more about the arrangement of atoms in solids, click here:

https://brainly.com/question/18924454

#SPJ4

A. Ca2+ < Cl− < S2−. Ca2+

B. Na+ < Br− < Rb+. Na+

C. 5s

D. B and Al

A. To place Ca2+, S2−, and Cl− in order of increasing radius, consider their charges and positions on the periodic table. The order is Ca2+ < Cl− < S2−. Ca2+ has a smaller radius due to losing 2 electrons and having a greater nuclear charge.
Cl− and S2− have gained electrons, but S2− has a larger radius because it's lower in the periodic table and has more electron shells.

B. To place Br−, Na+, and Rb+ in order of increasing radius, consider their charges and positions on the periodic table. The order is Na+ < Br− < Rb+. Na+ has a smaller radius due to losing an electron and having a greater nuclear charge.
Br− and Rb+ are in the same group, but Rb+ has a larger radius because it is lower in the periodic table and has more electron shells.

C. The ground state electron configuration for Sr (strontium) is [Kr] 5s². This is because Sr has 38 electrons, and when filling the electron shells following the aufbau principle, the last two electrons are placed in the 5s subshell.

D. To determine how many of the following elements have 1 unpaired electron in the ground state (B, Al, Se, Cl), look at their electron configurations:
- B (boron): [He] 2s² 2p¹ - 1 unpaired electron
- Al (aluminum): [Ne] 3s² 3p¹ - 1 unpaired electron
- Se (selenium): [Ar] 4s² 3d¹⁰ 4p⁴ - no unpaired electrons
- Cl (chlorine): [Ne] 3s² 3p⁵ - no unpaired electrons
So, 2 out of the 4 elements have 1 unpaired electron in their ground state: B and Al.

To know more about "Periodic Table " refer here:

https://brainly.com/question/12659384#

#SPJ11

Total, 12.5 percent of the initial sample of caesium-137 will remain after 100 years.

To calculate the percent of an initial sample that will remain after a certain time period, we can use the half-life of the radioactive isotope.

Given;

Half-life of caesium-137 = 30 years

Time period = 100 years

To determine the percent of the initial sample remaining after 100 years, we need to find the number of half-lives that have passed in that time period.

Number of half-lives = Time period / Half-life

Number of half-lives = 100 years/30 years

Number of half-lives ≈ 3.33

Since we cannot have a fraction of a half-life, we round this value down to 3.

After three half-lives, the remaining fraction of the initial sample can be calculated using the equation;

Remaining fraction = \((1/2)^{Number of half-lives}\)

Remaining fraction = (1/2)³

Remaining fraction = 1/8 ≈ 0.125

To convert this fraction to the percentage, we multiply by 100;

Percent remaining = 0.125 × 100 ≈ 12.5

Therefore, approximately 12.5 percent of the initial sample of caesium-137 will remain after 100 years.

To know more about half-life here

https://brainly.com/question/24710827

#SPJ4

The required force is 280 N.

We must subtract our individual forces in order to calculate the net force.

In general, whenever forces act on an object in opposite directions-the net force is equal to the difference between the two forces.

To calculate the net force, one force is subtracted from the other. therefore, here

325 N is force 1 to the right.

45 N is force 2 to the left.

Force 1 - Force 2 is the net force.

net force= 325N - 45N

net force= 280 N

So the required force is 280 N.

Learn more about force here:

https://brainly.com/question/13191643

#SPJ9

The net force of the runner would be 280 N.

Hope this helps! Also, if you need help with the other questions regarding this assignment, feel free to check out the study set I made on Quizlet. Thanks and good luck!

Quizlet - "Unit 6: Lesson 2 Newton's First Law QC"

h t t p s : / / q u i z l e t. c o m / 7 3 7 7 5 9 5 5 5 / u n i t - 6 - l e s s o n - 2 - n e w t o n s - f i r s t - l a w - f l a s h - c a r d s / ? n e w

Answer:

2) thin feather​

Explanation:

Cirrus clouds are delicate, feathery clouds that are made mostly of ice crystals. Their wispy shape comes from wind currents which twist and spread the ice crystals into strands.

hope it helps :)

please mark brainliest!!!

If the starting materials in the Tandem Green Diels-Alder Reaction were not added in a 1:1 ratio, it would impact the proton NMR spectra of the reaction mixture by altering the relative intensities of the peaks associated with the different protonated species in the mixture.

This would make it more difficult to determine the extent of reaction or to confirm the formation of the expected product.

As for using a different diene with a melting point of 100°C in a solvent-free methodology, it is not possible to determine if the reaction would be successful without further information about the reactivity and stability of the new diene under the reaction conditions. Solvent-free reactions can be challenging due to the need to control reactivity and solubility, and the melting point of the diene may affect its solubility and reactivity. If the diene is not sufficiently soluble or reactive in the reaction mixture, it may not participate in the reaction, leading to low yields or no product formation.

Learn more about proton:

brainly.com/question/1252435

#SPJ4

If the starting materials( (E,E)-2,4-hexadien-1-ol and maleic anhydride), in the Tandem Green Diels-Alder Reaction were not carefully added in a 1:1 ratio, but rather a 2:1 ratio, how would this impact the proton NMR? And If a different diene was used with a melting point of 100°C would you expect this reaction to be successful using a solvent free methodology?

Answer:

The Bohr model and all of its successors describe the properties of atomic electrons in terms of a set of allowed (possible) values. Atoms absorb or emit radiation only when the electrons abruptly jump between allowed, or stationary, states. Direct experimental evidence for the existence of such discrete states was obtained (1914) by the German-born physicists James Franck and Gustav Hertz.

Explanation:

Answer:

THE NUMBER OF ATOMS OF CHLORINE IN THE SAMPLE IS 25.95 * 10^45 ATOMS.

Explanation:

Number of molecules = 4.31 * 10^22 molecules of SCl2

From Avogadro's rule which states that equal volume of gases at the same temperature and pressure have the same number of molecules.

1 mole = 6.022 * 10 ^ 23 particles or atoms

So therefore, we equate the given value of SCl2 molecules and solve for the number of atoms of chlorine in the molecule

1 mole = 6.022 * 10^23 atoms

From the break down of SCl2

SCl2 -------> S+ + 2Cl -

So therefore, 2 moles of chlorine is present

2 moles = 2 * 6.022 *10^23

4.31 * 10^22 moles = x atoms

= 4.31 * 10 ^22 * 2 * 6.022 * 10^23 / 2

= 25.95482 * 10^45 atoms

In conclusion, the number of atoms of chlorine present in the sample is 25.95 * 10^45 atoms.

Answer:

Explanation:

This question is not very clear, however, going by the key words in the question, Archimedes' principle shows a relationship between mass and volume.

Archemedes' principle states that when a body is fully or partially immersed in fluid, it is acted upon by an upward force which is equal to the weight of the fluid displaced by the body.

The volume displaced here can be determined using the formula

Density of liquid = mass displaced ÷ volume

Hence, volume = mass displaced ÷ density of liquid

Answer:  T is the smallest non-metal other than noble gases.

Explanation:

Answer:

10 pts

Explanation:

The compound is 1- ethyl, 2,2,3,3 tetramethyl cyclopropane

The proper way to name a cyclic compound depends on the number of carbon atoms in the ring and the functional groups attached to it. Here are some general guidelines to follow:

Identify the longest continuous chain of carbon atoms in the cyclic compound. This will be the "parent" chain of the molecule.

Number the carbons in the parent chain so that the carbon atoms in the ring have the lowest possible numbers. If there are two or more possible numbering schemes, choose the one that results in the lowest numbers for the functional groups.

Name any substituents attached to the ring using the appropriate prefix and position number. If there are multiple substituents, list them alphabetically before the parent chain name.

Learn more about cyclic compounds:https://brainly.com/question/28195110

#SPJ1

Answer:

There is no hydrogen in the first half reaction

Answer:

B) The molecules were closer together when the juice pop was frozen.

Inhalation and exhalation as they relate to how gas is heated and humidified under normal conditions:

Inhalation:This process involves the drawing of air into the lungs of animals. The air breathed in is typically cooler and drier. The air is warmed and humidified in the nasal cavity and the rest of the respiratory system before it reaches the lungs.

The following happens during inhalation:A diaphragm, a sheet of muscle, contracts and descends, increasing the size of the chest cavity and lowering the air pressure in the lungs.

The intercostal muscles, which are located between the ribs, contract, causing the ribs to rise and expand the chest even further.Air is forced into the lungs due to the difference in pressure between the outside air and the lower-pressure air in the lungs.

Learn more about respiratory at:

https://brainly.com/question/9430523

#SPJ11

Protons, neutrons, and electrons make up around 0.999 of an atom's total mass for protons and neutrons, and 0.0005 of an atom's total mass for electrons.

Protons, neutrons, and electrons make up an atom's total mass. These particles' relative atomic masses may be used to determine what percentage of an atom's total mass corresponds to each one of them. A proton's relative atomic mass is one atomic mass unit (amu), a neutron's relative atomic mass is roughly one amu, and an electron's relative atomic mass is around 0.0005 amu. For instance, in a hydrogen atom with one proton and one electron, the proton's mass fraction would be around 99.999% of the total mass while the electron's mass fraction would be roughly 0.0001%.

learn more about mass here:

https://brainly.com/question/19694949

#SPJ4

Explanation:

to see how a change in a reactant concentration would affect the speed of the chemical reaction

Answer:

false

Explanation:

there are 3 oxygen atoms on the right and 2 on the left

Answer:

No

Explanation:

Right:

H = 2 atoms

O = 2 atoms

Left:

H = 2 atoms

O = 1 atom

+

O = 2 atoms

So the Right side has 4 atoms and the Lefts side has 5 atoms. Therefore, not balanced.

Answer:

Explanation:

Naming ionic compounds building a triangle so that each edge has the same answers facing each other

Explanation:

Each orbital within a particular sublevel is distinguished by its value of ml. This quantum number may be more aptly named the orbital orientation quantum number. In each energy sublevel (designated by l) there are 2l+1 possible independent orientations of the electron cloud.

Answer:

\(m_l-magnetic\)

Explanation:

The principal energy level, n, tells us which shell it is in and the total energy of the electron.

The angular momentum (azimuthal), l, tells us which sublevel/subshells the electron is in.

The magnetic, m sub l, tells us the orientation the electron is spinning.

Answer: 27 Hope it helps u

Question 5

Answer

D - 7.15 g O2

Explanation

Given:

Balanced chemical equation:

mass of Cr = 15.5 g

Required: mass of Oxygen

Solution:

Step 1: Find the moles of Cr

n = m/M where n is the number of moles, m is the mass and M is the molar mass

n = 15.5 g/51,9961g/mol

n = 0.298 mol

Step 2: Use stoichiometry to find the moles of O

The molar ratio between Cr and O is 4:3

Therefore the number of moles of O = 0.298 x (3/4) = 0.224 mol

Step 3: From the moles, we can find the mass of O

m = n x M

m = 0.224 x 31.998

m = 7.168 g which is closer to D = 7.15 g

When making a 0.250 M NaCl solution with a total volume of 300.0 mL, C. 4.38 g NaCl should dissolve in your 300.0 mL flask to make this solution.

NaCl must be added to prepare a 0.250 M solution of NaCl in a total volume of 300 mL. A solution is defined as a homogeneous mixture that is made up of two or more substances. The solute is dissolved in the solvent to make a solution. Concentration is defined as the amount of solute in a given amount of solution. When the solution concentration is expressed in terms of moles per liter (M), it is referred to as molarity. In a solution, the molarity is determined by dividing the number of moles of solute by the volume of the solution in liters.

To calculate the number of grams of solute required to prepare a given molar solution, the formula can be used given below:

Moles of solute = Molarity × Volume of solution (in liters)

The formula can be rearranged to calculate the number of grams of solute required as given below:

Number of grams of solute = Moles of solute × Molar mass of solute

For the given case, the molarity is 0.250 M and the volume is 300.0 mL.

To convert mL to L, divide by 1000: 300.0 mL = 300.0/1000 L = 0.300 L

Using the formula for moles of solute:

Moles of NaCl = Molarity × Volume of solution (in liters) = 0.250 M × 0.300 L = 0.075 moles of NaCl

Using the formula for grams of solute:

Number of grams of NaCl = Moles of NaCl × Molar mass of NaCl

Molar mass of NaCl = 58.44 g/mol

Number of grams of NaCl = 0.075 mol × 58.44 g/mol = 4.383 g

Therefore, C. 4.38 g of NaCl must be added to prepare a 0.250 M solution of NaCl in a total volume of 300 mL.

The Question was Incomplete, Find the full content below :

You want to make a 0.250 M NaCl solution many grams of NaCl with a total volume of 300.0 mL How should you dissolve in your 300.0 mL flask to make' this solution?

A. 1.73 g NaCl

B. 48.7 g NaCl

C. 4.38 g NaCl

D. 70.1 g NaCl

Know more about NaCl solution here :

https://brainly.com/question/23051191

#SPJ11

Answer:

Q = 5949.35 J

Explanation:

Given that,

The mass of water, m = 189.5 grams

Initial temperature, T = 16.4 °C

Final temperature, T' = 8.9°C

We need to find the thermal energy the water use to melt the ice cube. The thermal energy is given by :

\(Q=mc\Delta T\)

Where

c is the specific heat of the water, c = 4.186 joule/gram °C

So,

\(Q=189.5\times 4.186 \times (8.9-16.4)\\Q=-5949.35\ J\)

So, the required amount heat is equal to 5949.35 J.

The main precautions to take if a gas cylinder sign is present in the lab visually check that the gas cylinder is restrained, but keep a safe distance from it. The correct option is c.

Precautions are the preventive steps that are taken to save yourself from any dangerous circumstances. These steps are always taken in doing experiments and other scientific procedures.

Here, the precautions are to check the gas cylinder.

Thus, the correct option is c, Visually check that the gas cylinder is restrained, but keep a safe distance from it.

To learn more about precautions, refer to the link:

https://brainly.com/question/15622844

#SPJ4

The question is incomplete. Your most probably complete question is given below:

Remove the strap from around the gas cylinder to use it in the lab.

Open the valve on the gas cylinder periodically to release pressure.

Visually check that the gas cylinder is restrained, but keep a safe distance from it.

Test out the regulator on the gas cylinder to make sure it is working properly.

Answer:

Endoplasmic reticulum

Explanation: