Particle Physics

The largest atom is calcium which has 4 shells.

The minimum photonic energy required to create an electron-positron pair is 1.022 MeV. This energy is the equivalent of the rest masses of the pair of particles created. There is a bit more to this, as conservation of momentum must be observed. Pair production will occur, when it occurs, in the vicinity of an atomic nucleus when a high energy gamma ray zips in. The nucleus provides some "help" to "balance the equations" that describe the event, and that atomic nucleus will allow symmetry to be preserved. Specifically, that atomic nucleus acts in the conservation of momentum. That's why pair production won't occur as gamma rays are flying through the vacuum of space; there are (virtually) no atoms out there to facilitate the event. It may sound complex, but it's not all that difficult to get a handle on the phenomenon. A link is provided to our friends at Wikipedia. Knowledge there is free, and pair production isn't all that tough to understand. The article is brief and readable, and the complex equations that might have been posted are absent. Check it out.

When you remove a proton from an atom, it changes into a different element. The element becomes one with an atomic number one less than before, which affects its chemical properties. This process alters the balance of positive and negative charges within the nucleus, potentially leading to radioactive decay in certain situations.

Helium is the atom that will be inert, as it has a full outer electron shell that is stable and does not easily participate in chemical reactions.

The particles are closely packed together.

Yes, electrons are subatomic particles with a negative charge. They are found orbiting the nucleus of atoms and are fundamental components of matter.

Number of neutrons is 48 (mass number) minus 21 (proton number) = 27 (neutron number)

.000000000000000000000000000911 grams, or 9.11 x 10-34 kg

Protons are abundant in organic molecules, which makes proton NMR more sensitive and commonly used. 13C nuclei have a lower natural abundance and are less sensitive in NMR, requiring longer acquisition times and higher concentrations for analysis. However, 13C NMR provides complementary structural information and can help in resolving complex spectra.

DMSO-d6 gives a pentet in proton NMR due to coupling interactions with deuterium atoms in its structure. The two different types of deuterium atoms in DMSO-d6 cause splitting of the signal into a quintet pattern.

The three most commonly referred to subatomic particles are the proton, the neutron, and the electron. Protons and neutrons are the subatomic particles that reside in the atomic nucleus. Electrons, however, are located outside of the nucleus.

The subatomic particle in an atom that has no charge is called a neutron. Neutrons are found in the nucleus of an atom along with protons, which have a positive charge, and electrons, which have a negative charge.

neutrons have no charge at all, ther are neutral

The outer shell is called the valence shell

No, acids typically donate a proton (H+) rather than accepting a pair of electrons. Acids are defined as substances that can donate protons in chemical reactions.

Yes, the down quark is slightly heavier than the up quark. However, the difference in mass between a neutron and a proton is not solely due to the difference between the down and up quarks. Other factors, such as binding energy and contributions from virtual particles, also play a role in the mass difference between the two particles.

neutrons = 22 (for the most stable isotope of argon, Ar-40)

Work backwards. Positron emission means (essentially) a proton decayed into a neutron/positron pair. The mass number remains the same, but the atomic number goes down one to Bromine.

Krypton has an isotope that fits this bill.

Well, if you look at it in a purely elemental capacity we see trends that with an increase in electron shielding, we get a decrease in melting point.

This is said to be because with larger electron shielding we have a lower Z(eff) (effective nuclear charge) between atoms meaning weaker forces keeping them together and thus a lower melting point.

I think this is an important logical procedure when understanding why things melt and what things like Z(eff) really mean in terms of an atom's behaviour. It's a good learning tool but, outside of periodicity, I would never feel comfortable attributing a melting point to electron shielding. Good idea for elements, terrible idea for molecules.

Quarks have fractional electric charges because they are fundamental particles that carry one-third or two-thirds of the elementary charge. These fractional charges are a consequence of the way quarks interact through the strong nuclear force. Quarks are always found in combinations that result in integral charges when bound together in composite particles like protons and neutrons.

Wormholes and antimatter are not directly related. Wormholes are theoretical passages through spacetime that could potentially allow for faster-than-light travel, while antimatter is a form of matter that has properties opposite to those of normal matter. Both concepts are from the field of theoretical physics, but they address different phenomena.

Neutrons are a component of atomic nuclei and are not found as free particles in blood. Blood primarily consists of cells (red blood cells, white blood cells, platelets) and plasma (a liquid portion containing water, electrolytes, proteins, etc.), which do not contain neutrons.

This supposition is not true. Mutual annihilation, which occurs when a positron combines with an electron, will result in the conversion of all of the mass of both particles into energy. And this will result in the formation of two photons. The production of the photon pair is the result of conservation laws, and the two photons leave the event in opposite directions. Use the related link below to learn more.

It is postulated that the quanta involved in string theory are so small, so minute, and that they move at incredibly high speeds, so as to be everywhere they "need" to be, in order to account for all matter and energy of the universe.