A basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons.

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Atomic radii of Sc,Ti and Fe,Co

The atomic radii of Sc is 162pm , Ti is 147pm , Fe is 126pm and that of Co is 125pm. Electronic configuration of Fe is (Ar)3d6 4s2 and that of Co is (Ar) 3d7 4s2. Difference of Z between them is 1 ...
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55 views

Why Aren't Chlorides Of The Noble Gases As Prevalent As Their Fluorides?

I can't find the answer to this question on this SE website, and I apologize for the repetition if it has been answered before. It is my understanding that compound formation has only been observed ...
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34 views

What happens when we heat an atom?

Question is simple.. If we take an atom of any element and then supply heat energy to it then what will happen? Acc to me in beginning energy[quanta(due to excitement of electron and then moving ...
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39 views

Bombarding atoms with electron gun?

Just to explain this question in a better way just think about the Rutherford's experiment(the alpha particle bombarded on Gold foil) be conducted using a electron gun in place of the Alpha one.. So ...
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50 views

The definition of formal Charge

Ok, most people including me know that formal charge is just a book-keeping tool. I know how to calculate it, apply it to Lewis structures etc etc. But I am confused in its very basic definition which ...
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48 views

Greater entropy: an atom or macromolecule?

A question that appeared on my last chemistry exam was : Which of the following has greater entropy A) An atom B) A macromolecule The question doesn't specify anything else(i.e. type/size ...
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42 views

Wavelength of X-rays

What will be the wavelength of X-ray if we apply a potential difference of , say 20 KV across the ends of the x-ray tube ? Alright, i started with the modified de-broglie equation ...
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51 views

Intermolecular Hydrogen Bonding

I learnt about intermolecular hydrogen bonding today, which occurs between molecules such as ortho-nitro-phenol. What I was told is that in case of intermolecular bonding, the molecules separate from ...
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51 views

Why are atom spherical in shape ?

I am learning about structure of atom, in which i saw right from J.J. Thomsom atomic model to modern nuclear atomic model all are spherical in shape. I have seen how different discoveries help to ...
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39 views

Shells, orbitals, subshells, and energy levels

I think i Know what these mean, each row on the periodic table has a new shell of electrons, a subshell is e.g. 1s, 2s, 2p, 3s, 3p, etc and energy levels are the same as shells whilst orbitals are the ...
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Why don't alkaline earth metals lose only one electron when they are ionized?

Why doesn't alkaline earth metals lose only one electron when they are ionized ? I know that magnesium atoms like to have the electronic configuration of neon but I don't understand the reason that we ...
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42 views

Find the uncertainty in position

The question says: A proton is accelerated to one tenth of the velocity of light. If it's velocity can be measured with a precision $\pm 1\%$. What must be its uncertainty in position? Therefore, ...
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59 views

Calculating Avogadro's Number

For a school project, I am in a group tasked with calculating Avogadro's Number in multiple manners. Other than the Millikan Oil Drop Experiment, we know of no ways to compute it. A Google search ...
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33 views

Finding out the number of atoms in the sun.

This is the question from the text book: This is what I did, since it worked with all the previous questions (similar to this). $$ \frac{\frac{4}{3}\pi(7*10^8)^3*1.4}{1.008} * 6.022*10^{23} $$ ...
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85 views

Law of reciprocal proportion

Is it necessary that the valency of an element must have the same valency? For eg. If 2 elements A and B combine with the same mass of C, is it necessary that they will have the same valency as they ...
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67 views

Degenerate Orbitals

How do I know if an atom has degenerate orbitals? My Understanding I understand that degenerate orbitals mean orbitals that have the same energy level for the same n. However, how do I distinguish ...
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92 views

How to calculate m/e value for the base peak in mass spectroscopy?

My working out: Propan-1-ol : CH3CH2CH2OH This can be broken up into: CH3 + CH2CH2OH CH3CH2 + CH2OH CH3CH2CH2 + OH Base peak = most abundant fragment formed (highest peak) How do i know which ...
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103 views

Is it possible to compress an atom to infinite density?

I know, by nature, normally atoms are stable. But I wonder, if it is possible to compress an atom, say the Hydrogen atom, to infinite density by applying external force? After all, electrons and ...
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Are atoms really round?

I'm not sure if this is a silly question, but I was sitting here with a cup full of cheezey poof balls thinking, "My goodness, it's like an amazing cheesey delicious liquid - huge water molecules!" ...
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Why does free chlorine in the stratosphere lose its ozone-depleting potential after about 100,000 reactions?

Free chlorine ($\ce{Cl}$) in the stratosphere can deplete ozone ($\ce{O3}$) as follows: $$\ce{Cl + O3 -> ClO + O2}$$ The chlorine atoms can then react with oxygen and return to the beginning of ...
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117 views

Number of molecules and atoms are same in a gas, how?

I had a test this morning in school and I am not sure of the answer,I think it is related to the quantity of a mole being constant: A sample of certain mass of gas was collected and it was found that ...
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27 views

Comb and hair, is that an example for ionic boding?

As i understand, when brushing hair, some electron transfer from hair to the comb. Thus, make the comb have different charged from hair and they attract each other. It's look likely what i have learn ...
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57 views

Ground state electron configuration of chromium

What is the ground state electron configuration of chromium? Is it [Ar]4s23d4 or Is it [Ar]4s13d5
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Electrons and their affect on the atomic radius [closed]

What happens to the atomic radius when an magnesium atom loses an electron? What happens to the atomic radius when a sodium atom loses an electron?
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What is the largest possible element? [duplicate]

I assume there is a limit to the number of protons in a nucleus. If so, there should be a theoretical atomic number that no element can exceed. So, what is the largest possible atomic number? Is such ...
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52 views

Photoelectric effect and electron loss

I've read that when a certain amount of UV light is shone on a metal surface, electrons are ejected (the photoelectric effect). Are these electrons from the metal atoms themselves? and in case they ...
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78 views

Cathode Ray Tube

I am considering the cathode ray tube of the set up, when the cathode rays were discovered Voltage = Very High Gas = any Atmospheric Pressure = We change (In the following example i am just changing ...
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72 views

Why aren't atomic radii calculated using Schrödinger's equation?

The atomic radii are estimated using a variety of methods: most of these involve dividing their bond length by 2. But that is a very crude way of measuring atomic radii. I mean, atoms overlap each ...
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64 views

Reason for vibration of molecules

Why molecules of a body exhibit vibrational motion ? Is it due to interaction between various molecules of the body or inter atomic interaction of the same molecule? If it is because of any of them ...
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34 views

Comparision of donation power

There is a group R an organic group connected to either Oxygen or Nitrogen.R is such a group which has almost zero electronic effects(Resonance effect and inductive effect).I want to ask if N or O are ...
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211 views

The last element's atomic number

I was just thinking what can be the last atomic number that can exist within the range of permissible radioactivity limit and considering all other factors in quantum physics and chemical factors.
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160 views

How do I calculate the change in energy of an electron transition?

What are the $\Delta E$'s of the transitions of an electron from $n=5$ to $n=1$ and from $n=5$ to $n=2$ in a Bohr hydrogen atom? The wavelength of the first electron transition is ...
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45 views

Comparision in ionization enthalpy of Cs and Fr

Why ionization enthalpy of Fr is greater than Cs even though it have larger size. I found no google result regarding.
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833 views

Is there an easy way to find number of “valence electrons”?

I want an high-school level answer.What I mean with "valence electrons" is the outermost electrons in that atoms' electronic arrangement?(eg. $3$ in an atom with electronic arrangement $2,8,3$) ...
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80 views

Types of Radioactive Decay

Besides Alpha, Beta, and Gamma, are there any other types of radioactive decay? If so, what are they? Is there any type of radioactive decay more powerful than Gamma?
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239 views

How many electrons can each shell in an atom hold?

I know that the first shell can hold 2, the second and third 8, and the fourth 18. But what about after that?
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565 views

Iodate ion (IO3-). Is it polar or non-polar?

I am trying to figure out the shape of the iodate ion or $\ce{IO3^-}$. No matter how many times I draw it, I keep getting Iodine in the centre, and 3 oxygen atoms surrounding it, 2 with single bonds, ...
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141 views

If atoms are mostly empty space then how are we able to interact with things?

Note: This question has come out of curiosity Q: We all have read that atoms are mostly empty, they are generally compared to a football stadium in which a pea is kept in the center(nucleus) and flies ...
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46 views

What are the known atomic oxygen species?

I'm interested in chemical reaction mechanism with more exotic particles. The Wikipedia page seems to imply that the normal atomic oxygen is $O(^3P)$, is that right? I also came across ...
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50 views

Atomic properties

This may be a very broad question. I always asked myself how scientists manage to find out the exact molecular structures of for instance water or carbohydrates. How do they know? How do they know the ...
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134 views

Critical separation at which molecule breaks

I have the following question. The potential energy of two atoms, a distance $r$ apart, is: $$U = -Ar^{-2} + Br^{-10}$$ Given that the atoms form a stable molecule at a separation of 0.3nm with an ...
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In nuclear chemistry, how does a neutron split to form a proton and an electron?

I'm studying radioisotopes at the moment and balancing nuclear reactions isn't making sense in that more matter is coming out of the equation in negative β decay equations : ...
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107 views

Wasn't Rutherford's assumption of gold foil to be made of single layer wrong?

My teacher taught about Rutherford's gold foil experiment today. Sir said that, Rutherford used gold foil of thickness $10^{-7}$ m and concluded atom to be of size $10^{-10}$ m. Sir also said that ...
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102 views

How will these hydrogen atoms interact?

Assume that we have a space with just two $\ce{H}$ atoms and their distance to each other is $d$. Let's say they don't have initial velocity. What is the force with which they will act on each other? ...
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130 views

Magnetic moment of coordination complexes?

To understand the commonly quoted magnetic values of coordination complexes (central ion) we use $$m_l=\sqrt{n(n+2)} \text{BM where BM}=\frac{e\hbar}{2m_e}\text{JT}^{-1}$$ $n$=number of unpaired ...
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Understanding moseley's law from the rydberg-type equation?

To explain the characteristic X-ray emission peaks for various elemental targets, a formula was developed which was similar in construct to the rydberg equation for H-atom as derived by the ...
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213 views

Are orbitals always filled in from closest to nucleus to farthest away?

On a review sheet for a quiz I have tomorrow, I have a question like this: "In which orbital, 4f or 6s, would an electron have a greater likelihood of being near the nucleus". I figured that the 6s ...
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735 views

Is ionic bond just formed by “electrostatic” interaction between two oppositely charged ions?

According to the definition of ionic bond: An ionic bond is a type of chemical bond formed through an electrostatic attraction between two oppositely charged ions. If we consider the above ...
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126 views

How do 1s and 2p orbitals overlap?

In the following figure we can see that the p-orbitals overlap 1s orbital (though relatively very little). How can an electron in p-orbital, be simultaneously in the 1s orbital at any given point ...
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Why do people still use the mole (unit) in chemistry?

I know that the mole is widely used in chemistry instead of units of mass or volume as a convenient way to express amounts of reactants or of products of chemical reactions. I'm wondering why people ...