A man receives a platinum ring from his fiancee. Before the wedding, he notices that the ring feels a little light for its size and decides to measure its density. He places the ring on a balance and finds that it has a mass of 3.15 grams. He then finds that the ring displaces 0.233 cm3 of water. Given that the density of pure platinum is 21.4 g/cm3, is this ring genuine

Answer:

Ar

Explanation:

1s2|2s2 2p6|3s2 3p6 means 2+2+6+2+6=18 electrones. Also it means the number in the table.

According to the №18 the requested element is Argon.

The element argon with atomic number 18 is found to has the electronic configuration 1s² 2s² 2p⁶ 3s² 3p⁶. Here the element 'Ar' belongs to the 18th group of the periodic table.

The electronic configuration is defined as a method which represents the arrangement of electrons in the atomic orbitals. Each of the elements have a unique electronic configuration.

The physical, chemical and magnetic properties of the elements can be predicted by knowing their electronic configuration. Sometimes the term electron structure can also be used instead of electronic configuration.

The species K⁺ ion has the same electronic configuration of 'Ar'. The atomic number of 'K' is 19 and  K⁺ is formed by the lose of one electron from 'K'. Here  K⁺ has 18 electrons and its electronic configuration is:

1s² 2s² 2p⁶ 3s² 3p⁶.

Thus the element argon has the electronic configuration 1s² 2s² 2p⁶ 3s² 3p⁶.

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Answer:

Although he was unaware ofit, Mendeleev had actually placed the elements inorder of increasing “atomic number,” a numberrepresenting the amount of positively charged protons in the atom (also thenumber of negatively charged electronsthat orbit the atom). Mendeleev went even further.

Answer: 67.4%

Explanation:

Ca 40.8

W. 183.8

O. 16.00

CaWO3 272.6

W = 183.8/272.6 = 0.674

67.4% percent by mass of tungsten in the calcium tungstate compound CaWO3, commonly called scheelite.

The 200 Speed Blue Emitting Calcium Tungstate Screen is the most commonly used Non-Rare Earth intensifying screen. With a faster speed than Detail or Medium speed screens, the Hi-Plus Intensifying Screen provides an efficient balance between the time patients are exposed during x-rays and image quality and detail.

It was also used in radium paint in the same fashion as was zinc sulfide, and Thomas Edison invented a fluoroscope with a calcium tungstate-coated screen, making the images six times brighter than those with barium platinocyanide; the latter chemical allowed Röntgen to discover X-rays in early November 1895.

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Answer:

th relative ability of a solute to devolve into a solvent

Answer:

I think it's B- it is transparent

Answer:A

Explanation:Glass can not be classified as a crystal when it is in its amorphous phase.

Answer: Pb(NO3)2(aq) + 2KI(aq)  —> PbI2(s) + 2KNO3(aq)

Explanation:

Answer:

software is a collection of codes installed onto your computer hard drive and hardware is any physical device that we used in or with your machine.

hope it helps.

Answer: soft water is water with a low concentration of ions and hard water is one with a high concentration of water e.g rainwater

Explanation:

Answer:

hello your question is incomplete attached below is the complete question

answer :

we use Isomerization because conjugated allylic carbocation  is more stable when compared to a Non-conjugated Allylic carbocation

Explanation:

Reason for the mechanism

we use Isomerization because conjugated allylic carbocation  is more stable when compared to a Non-conjugated Allylic carbocation

attached below is the detailed mechanism

Answer:

C solution

Explanation:

i hope that i got it right im not very good with questions

Answer:

C₂ =  0.52 M

Explanation:

Given data:

Initial volume = 334.75 mL

Initial concentration = 1.28 M

Final volume = 822.18 mL

Final concentration = ?

Solution:

C₁V ₁     =     C₂V₂

By putting values,

1.28 M×334.75 mL = C₂×822.18 mL

C₂ =  1.28 M×334.75 mL / 822.18 mL

C₂ =  428.48 M.mL / 822.18 mL

C₂ =  0.52 M

Answer:

Because each element has an exactly defined line emission spectrum, scientists are able to identify them by the color of flame they produce. For example, copper produces a blue flame, lithium, and strontium a red flame, calcium an orange flame, sodium a yellow flame, and barium a green flame. When you heat an atom, some of its electrons are "excited* to higher energy levels. When an electron drops from one level to a lower energy level, it emits a quantum of energy. ... The different mix of energy differences for each atom produces different colors. Each metal gives a characteristic flame emission spectrum

Answer:

1. B 2. C 3. A

Explanation:

I just took it

Limiting reactant is the reactant the produces the least amount of the product.

In a chemical reaction, the reactant that is in least supply is the limiting reactant while the reactant that is more than required is the excess reactant.

To match each term with its description, we have;

the product

amount of the product

produced by the given reactants

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Answer:

The true statement about semi-empirical methods is:

It combines a theoretically sound model of bonding with some experimentally determined parameters.

Explanation:

Semi-empirical methods are theoretical assumptions combined with experimental data to improve computational performance.  In modern computational chemistry, semi-empirical methods play important roles. The methods offer the advantage of a substantial reduction in computational time.  They also increase one's ability to carry out calculations for large molecules.  However, with these methods, there is the added loss of the variational principle because one can obtain a total energy that is below the true total energy.  Again, semi-empirical methods have limited applicability because the methods apply to molecules with parameterized elements.  Semi-empirical methods may supply spurious results, especially since the molecular systems may be different from those used for parameterizations.

The molecular formula : C₁₈H₁₈N₈

Given

62.41% C, 5.24% H, and 32.36% N

Required

The molecular formula

Solution

mol ratio

C : 62.41/12.0096 = 5.1967

H : 5.24/1.00784 = 5.1992

N : 32.36/14.0067 = 2.310

Divide by 2.310(smallest)

C : 5.1967/2.31=2.25

H : 5.1992/2.31 = 2.25

N : 2.31/2.31 = 1

Multiplied by 4

C : H : N = 9 : 9 : 4

The empirical formula : C₉H₉N₄

(C₉H₉N₄)n=346.40 g/mol

(12.0096 x 9 + 1.00784 x 9 + 14.0067 x 4)n=346.4

(108.0864+9.07056+56.0268)n=346.4

(173.184)n=346.4

n=2

The molecular formula : C₁₈H₁₈N₈

Answer:

9.64 x 10^22

Explanation:

To go from moles to molecules, you multiply by Avogadro's number, 6.022 x 10^23, so you get 9.64 x 10^22.

Answer:

O The clothing company conducted a scientific  investigation to communicate results to researchers,  who then used the knowledge in a technological

design.

Explanation:

The products of scientific investigation are converted into technology for use engineers.

Engineering is the application of science to solve life problems. Science in itself is an inquiry into nature.

Answer:

Their must be a picture with this question so we can answer it

Explanation:

According to octet rule  the bonded valence shells are completely filled. All the compounds except the first one, CH₃CH₃O is invalid since H does not obey the rule and invalid.

Octet rule says that an atoms become stable when it completes its valence shell to 8 electrons or 2 electrons for K-shell. Thus bonded shells have to completely filled to be stable.

Each atom shares its electrons based on its valency. For example carbon have a valency of 4 and it forms for bonds and oxygen and sulfur have two and hydrogen forms only one bonds.

In the first compounds CH₃CH₃O, where one H forms two bonds which is not possible and invalid.

In the second compound CONH, all the atoms satisfies its valency including nitrogen having a valency of three forms  three bonds. Similarly in CH₂F₂, one fluorine forms one bond and the structure is valid.

In the case of Br₂ , each bromine shares one electron with the other and complete their octet to eight electrons. In NH₃, SCO and COCl₂ all the atoms satisfies their valency and the structures are valid.

Therefore the only invalid structure is first compound, remaining all are valid.

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Your question is incomplete. But most probably your complete question was as in the uploaded image.

Answer:

26g

Explanation:

Given parameters:

Density  = 8.96g/cm³

Volume of metal = 2.9mL

    Since 1mL  = 1cm³;

          Volume  = 2.9cm³  

Unknown:

Mass of the blocks in grams  = ?

Solution:

Density is the mass  per unit volume of a substance;

   Mass  = density x volume  = 8.96 x 2.9  = 26g

Answer:

Explanation:

Normal boiling point = 141.7°C

Elevated boiling point = 142.5°C

Elevation of boiling point Δt = 0.8°C

Formula for elevation of boiling point is as follows .

Δt = 1000 x Kb x w / (MW )

where w is weight of solute , M is molecular weight of solute , W is weight of solvent in grams,  Kb is molal boiling point elevation constant .

Mol weight of barium hydroxide = 171 .

.8 = 1000 x Kb x 68.1 / (171 x 750 )

Kb = 1.5°C / m

Answer:

follow the picture,,, it includes the normal elements too

The reason why I organized these specific elements from the list of elements that you provided me is because they have to do with color. I believe organizing by color would be much easier for me to understand. There is also a somewhat equal amount  for each color. For example I used the colors: orange, green and red In my chart because there are four of each color in the list you provided me.

Answer:

false

Explanation:

chemical changes turn into new substances

Answer:

6moles of Mg

Explanation:

The reaction expression is given as:

          BO₃   +    3Mg   →    3MgO    +    B

Given:

Number of moles of B produced  = 2 moles

Unknown:

Number of moles of Mg required  = ?

Solution:

  From the balanced reaction expression:

          1 mole of B is produced from 3 moles of Mg

          2 moles of B will be produced from 2 x 3  = 6moles of Mg

Answer:

yep C is correct!!

Explanation:

Answer:

The IUPAC name of the compound has already been given which is 2,2-dimethyl-4-ethylheptane.

Explanation:

The IUPAC (International Union of Pure and Applied Chemistry) is an authority in chemistry that provides a guideline and standardized methods in the naming of compounds formed from the periodic table.

In order the give an IUPAC name to a compound, certain steps needs to be followed, these includes:

--> Identify the functional group in the compound as this will form the suffix. For example if the functional group is an alkane the suffix will be -ane.

--> Identify the longest carbon chain (it may not be a straight chain) that contains the functional group. This forms the prefix. Example: if the longest carbon chain is 7 carbon atoms then the prefix will be hept-

--> All the carbons of the longest chain should be numbered

--> Identify branched groups on the chain and name them according to the number of carbon atoms. They usually end with -yl.

--> Finally, combine the elements of the name is a single word.

The structural formula of the IUPAC compound can be found in the attached file for a better understanding. The branched groups are circled.

Answer:

halogen.

nonmetal.

Explanation:

Answer:

H-H equation is written as follows:

pH=pK + log

{HCO3-}(base)

{H2CO3}(acid)

Moles of phosphoric acid would be needed : 0.833

Given

15 grams of water

Required

moles of phosphoric acid

Solution

Reaction(decomposition) :

H3PO4 -> H2O + HPO3

mol water (H2O :

= mass : MW

= 15 g : 18 g/mol

= 0.833

From the equation, mol ratio H3PO4 = mol H2O = 1 : 1, so mol H3PO4 = 0.833