Nuclear Physics

Yup, by doing the "Gold Foil Experiment" he found that most particles went straight through a sheet of gold foil, while only a very tiny percent was deflected. This meant that the atom was mostly space, it had a tiny solid core called a nucleus, the nucleus is positivley charged and he beleived that the electrons surrounded the nucleus like how planets orbit the sun.

Radioactive materials have unstable nuclei. That's what makes them what they are. The nucleus of a radionuclide will eventually decay. The time that must pass before this happens, and the manner in which the decay will take place vary from one radioisotope to another. As regards the length of time to decay, we cannot know for a given atom of a radionuclide just when it will decay. Certainly we can (and do) find what is called a half-life for each radioisotope. This is a statistically arrived at "average" for the length of time it will take for a given radioisotope to "lose" half its mass to decay. While we can't know when a given atom of something will decay, we can find, and with a great deal of accuracy, the length of time it will take for half of a large number of atoms of a given radionuclide to decay. When it comes to modes of radioactive decay, there are several, and each radioisotope has one of the modes as its own (though there are a few radionuclides that have a couple of different possible decay schemes). The decay schemes are spontaneous fission, alpha decay, beta decay (several kinds), proton emission, double proton emission, neutron emission, and cluster decay. This short post hits the nail on the head. More information is certainly out there, and Wikipedia has some good stuff posted. You'll find a link below to material that is on point.

Yes, Rn is radon a radioactive nonmetal.

But the symbol Rn does not stand for "radioactive nonmetal."

Rn Radon has no stable isotopes, so yes it is always a radioactive nonmetal.

The electron shell is the source of an element's chemical properties and the moderator of chemical reactions; the electron shell depends on the protons that constitute the atom

The main advantage of the transmission electron microscope is its high resolution, allowing for the visualization of internal structures at the nanometer scale. This microscope can reveal details of the ultrastructure of samples with great clarity, making it useful for studying materials and biological specimens at the atomic level.

The charge of an electron is -1. Specifically, it is about -1.602 x 10-19 coulombs. The mass of an electron is about 9.109 x 10-31 kilograms, or about one 1836th that of a proton.

The spontaneous process in which unstable nuclei emit radiation is called radioactive decay. During this process, the unstable nucleus releases energy in the form of alpha particles, beta particles, or gamma rays in order to become more stable.

No, underground nuclear tests cannot alter the Earth's axial tilt. The axial tilt of Earth is determined by gravitational interactions with other celestial bodies and is not influenced by nuclear tests.

A liquid-in-glass thermometer works based on the principle of thermal expansion. As temperature increases, the liquid inside the thermometer expands and rises in the calibrated glass tube. The level of the liquid indicates the temperature which corresponds with a specific scale on the thermometer.

the process by which multiple like-charged atomic nuclei join together to form a heavier nucleus. It is accompanied by the release or absorption of energy, which allows matter to enter a plasma state.

• nuclei have an overall positive charge, as they contain both protons and neutrons
• anti-nuclei have an overall negative charge, as they contain both anti-protons and anti-neutrons

Yes, in general. All hydrogen atoms contain one proton, most with no neutrons and all neutral atoms with one electron - and the electron has a much smaller mass. Some hydrogen atoms contain one (or, rarely, two) neutrons and so are heavier. But on average the atom has a mass much the same as a proton.

beta

The main constituents to the atom are the protons (p+) and neutrons (n) of its nucleus, and their orbital electrons (e-). The p is notated with a positive charge, while the e- is negative -1.

You can imagine the electrons as being in a similar situation as the planets that circle the Sun. The centripetal force is the attraction by the Sun (for planets), and by the nucleus (for electrons). Remember that opposite forces attract each other.

Actually the situation is more complicated, due to certain quantum phenomena, but this should give you a general idea. Specifically, electrons are not free to travel in any orbit - they can't have just any energy, they can only be at very specific energy levels.

The smallest part of matter that still functions like matter is called an atom. The atoms make up molecules that in turn make up cells.

The term is called half-life. It is the time it takes for half of the radioactive nuclei in a sample to decay.

A meson is made of quarks - specifically a quark-antiquark pair. Some are called pions and kaons. They are all short lived particles that have been identified from high energy collisions. See Wikipedia for more detail.

A neutron has no charge, as it is electrically neutral.

The half-life of the radioactive substance is 13.8 days. This is calculated by dividing the natural logarithm of 2 by the decay constant, which is obtained from the percentage disintegration in a given time period. In this case, 0.1 (10 percent) disintegrates in 4 days.

Quarks are the smallest known fundamental particles that make up protons and neutrons, which in turn make up atomic nuclei. Quarks are never found in isolation, but always in groups of two or three to form the building blocks of matter.

In positron emission, atomic number decreases by one. That's because a proton in the nucleus of the element that is about to undergo positron emission changes into a neutron. This is beta plus decay, by the way. You'll recall that the atomic number of an element, which is that element's chemical identity, is determined solely by the number of protons in the nucleus. If we "lose" a proton because it changes into a neutron, atomic number will now decrease by one. Check out the links below to related posts.

This is the early relaxation of the particles. It corresponds to the vibrations of the particles around their equilibrium position, and is not very informative in itself : the particles are stuck by their neighbors, and this leads to a plateau of relaxation (beta relxation is before the plateau).
The late relaxation is called alpha relaxation, and is much more inofrmative on the dynamical heterogeneities at play for instance in glass formers.