Some clarification in your question would be desirable, for you could be asking about the nucleus of an atom or the nucleus of a Eukaryotic cell.
The simple answer for both is to relate it to a soap bubble (free floating). They are a circle (sphere) for the same reason that a bubble ultimately forms a sphere. The sphere is the shape with the largest volume to surface area ratio, i.e. the shape with the least amount of expended energy to hold (in that shape). The more complicated answer is that a cellular nucleus is not always a perfect sphere, it is maleable, but just like the soap bubble, given no outside influence, it will rebound into a more or less spherical shape. An atomic nucleus is represented as a sphere for roughly the same reason, i.e. conservation of energy. Restraints on the spherical nature would be the type of atom, and whether or not the protons and neutrons are balanced in number. Nevertheless, it will hold a more or less spherical shape.
In this model, the electrons move or orbit around the protons that are at the center of the atom. Electrons move around the nucleus, which contains the proton, in orbits that have a definite size and energy.
The plural of nucleus is nuclei. It derives from the Latin word nucleus, which means "kernel."
I need a picture of a nucleus can i please get a picture of a nucleus
No, protons do not orbit the nucleus in an atom. They are located within the nucleus along with neutrons. Electrons are the particles that orbit the nucleus in an atom.
Nucleus
You are probably referring to the electrons. It doesn't exactly "circle" the nucleus of an atom, but it does exist in an orbit around the nucleus.
You are probably referring to the electrons. It doesn't exactly "circle" the nucleus of an atom, but it does exist in an orbit around the nucleus.
The electrons circle the nucleus in specific orbits.
Electrons are the particles that circle the nucleus of an atom.
Electrons are the particles that circle the nucleus of an atom.
Electrons are the particles that circle the nucleus of an atom.
Electrons are the particles that circle the nucleus of an atom.
Electrons are the particles that circle the nucleus of an atom.
Protons are in the nucleus of an atom along with the neutrons. The electrons circle the nucleus in "shells".
No, neutrons are in the center (nucleus) of the atom.
it is the little circle in the middle of the cell
In an atom, electrons move around the nucleus, which contains both protons and neutrons. Protons and neutrons are found in the nucleus, while electrons move in orbitals around the nucleus. The orbits of electrons are complex and not necessarily circular.