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

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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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52 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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28 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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76 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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101 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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25 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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47 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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21 views

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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20 views

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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44 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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73 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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1answer
66 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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1answer
58 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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29 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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160 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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99 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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40 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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351 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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55 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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93 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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357 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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64 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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44 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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49 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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124 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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75 views

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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90 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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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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98 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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167 views

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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1answer
170 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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452 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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114 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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397 views

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 ...
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Finding the number of orbitals on a central atom

In $\ce{BeCl2}$ the number of orbitals on central atom, i.e. on beryllium, are 2. In $\ce{BF3}$, the number of orbitals on central atom , i.e. on boron, are 3. Similarly in $\ce{NH3}$ there are 4, ...
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What determines the density of an element?

I used to be under the (wrong) assumption that the density of an element correlates with it's atomic number $\mathrm{Z}$, I thought that since having more protons meant the atom weighed more; but of ...
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468 views

Sulfur trioxide - vacant d-orbitals

Sulfur trioxide violates the octet rule. Upon drawing the Lewis dot structure for sulfur trioxide, we see that the central sulfur atom is bonded to three other oxygen atoms by double covalent bonds. ...
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140 views

Storing kinetic energy in bonds

Let's assume a setup with a static linear molecule with three identical atoms connected by bonds and a single atom, identical to the other three, being shot at the molecule. Let's also assume that ...
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186 views

How many molecules of O2 are needed to oxidise 25g of Mg? [closed]

I thought it may be easier to show my working from my workbook.
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How to find the number of valence electrons?

I need to understand the following: Considering an element Sulfur - S which has 16 electrons. How do we calculate the number of valence electrons of S? Please correct me if I am wrong:2+2+6+2+4=16. ...
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(Organic Chemistry) Common Atoms in Organic Molecules [closed]

What are 6 atoms commonly found in organic molecules?
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421 views

Z* effective charge and Ionization Energy

I'm trying to figure out the patterns for Ionization Energies. I am familiar with the periodic trend, however things become quite different when we hit the 1st I.E. For example, Na has an I.E(1) of ...
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69 views

How do the differences in the number of protons result in such great differences in elemental properties?

I understand(I think) the mass and density aspect, i.e. the more protons you have, the more the element weighs, also the denser the atom is. What about everything else(color, for example)? Elements ...
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160 views

What gives atoms their chemical properties

For example, what makes Hydrogen flammable, what makes Oxygen support burning and what makes water behave unlike either components? The crux of the question is, what gives an element its chemical ...
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295 views

Degeneracy of orbitals?

Why is that in an external magnetic field(uniform) the degeneracy of d,f orbitals is lost but the degeneracy of p orbitals remain intact if the main cause of losing degeneracy is the difference in ...
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193 views

Confusion about the charge of electrons while orbiting through bohr's energy shells

I came across the following part in my text book. Bohr's atomic theory explained the stability of an atom by the idea of energy shells. He said that while orbiting the nucleus through a particular ...
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1answer
124 views

Can there exist any element which has an 8th principle shell?

I am a high school student . While studying the atomic structure a question raised in my mind. We know that an atom can have the highest limit of 7 bohr energy shells or principle energy shells ; ...
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How to get the valencies of elements?

How to find the valencies of elements by using it's distribution of electrons? Explain the method in simple words? Do you have to study the valencies or is there is a simple way of remembering? PS: ...