I hate these kinds of questions, because the mental picture most people have of atoms is so very wrong it's hard to know where to start.
When talking about electrons in atoms, the first thing to know is that they're in orbitals, which are not at all the same thing as orbits. They're not going around and around in circles, they're... somewhere inside a sort of "cloud", and are more likely to be found in some regions of the "cloud" than in others.
There are equations that describe the probability of finding an electron in a given orbital at a particular point in space. These equations are called "wave functions," and are pretty complicated. If you really want to know, I recommend two books in particular: either Levine's Quantum Chemistry (better if you're approaching things from the chemistry side and/or want all the details at an advanced level) or Feynman's Lectures on Physics, volume III (better if you want more of an overview at a college sophomore physics level, or are more of a physicist). Both of these will be in any good college library, and may be in some public libraries with better-than-average science sections (the Feynman in particular).
Multiplying these equations in a particular way and integrating them gives you the probability density... how likely it is to find an electron to be in a particular region. The interesting thing about these probabilities is that they have nodes... regions of space where it's actually impossible to find the electron, though it could potentially be found on either side. For example, a p-type orbital has a nodal plane. The electron can be above the plane or below the plane, but (and this is the part that gives most people conniptions, the first time they run across it) it can never be found in the plane itself. Not even briefly. Not even "just passing through." So how does it get from one side to the other? It... just does. And all the math works out. But to really understand it, you've got to forget pretty much everything you think you know about how the universe works, and learn to trust the math.
Most of the mass of an atom is located in the nucleus, which is made up of protons and neutrons. The nucleus is located at the center of the atom. Electrons, which have much less mass compared to protons and neutrons, orbit around the nucleus in electron clouds.
yes, they are called groups.
the periodic table of elements is arranged by what?
Mendeleev's scheme was different from the modern periodic table because he listed the elements in order according to the relative atomic mass. Dmitri Mendeleev created his periodic table in 1868.
The atomic number is used to determine the order of the elements on the modern periodic table. The atomic number represents the number of protons in the nucleus of an atom, which defines the element. Elements are arranged on the periodic table in order of increasing atomic number.
According to modern atomic theory, electrons can move from one energy level to another within an atom. This movement between energy levels is responsible for the emission or absorption of electromagnetic radiation in the form of photons.
Most of the mass of an atom is located in the nucleus, which is made up of protons and neutrons. The nucleus is located at the center of the atom. Electrons, which have much less mass compared to protons and neutrons, orbit around the nucleus in electron clouds.
The modern periodic table is arranged according to the elements' atomic numbers.
Symbol, Name, Atomic Number, Atomic Mas, Energy Levels, Electrons
The Bohr atom imagined that electrons orbit the nucleus in much the same way that planets orbit the sun. The modern atomic model has electrons in the form of a cloud that surrounds the nucleus without actually moving in orbit around it. Moving electrons would have to emit photons, lose energy, and spiral into the nucleus, thus destroying the atom. They don't really orbit.
In Dalton's theory the electrons in the atom travel in a one layered orbital rotation around the nucleus, in the modern, or electron cloud, theory the electrons travel in a more radical patterned movement while still staying in their respected energy levels.
The arrangements of the electrons are diffrent.
Electrons are most likely to be found in the electron cloud surrounding the atomic nucleus.
you cannot determine its electronic configuration through its atomic mass. atomic no is necessary. for this, check modern periodic table.
The Modern Periodic Law states that there will be a periodic repetition of properties when the elements are arranged according to increasing atomic number.
According to modern atomic theory, it is nearly impossible to determine an electron's exact position and momentum simultaneously. This is known as the Heisenberg Uncertainty Principle, which states that the more precisely one property is measured, the less precisely the other can be known.
according to the increasing atomic number.