The force that keeps electrons in orbit around the nucleus is called the repelling force of gravity. If there was no gravity the electrons would never stay in orbit but would be floating around in space.
Repelling Force of Gravity
It is somewhat misleading to say that anything orbits the center of an atom. There is an electron cloud that surrounds the center of the atom, but the electrons do not actually orbit, they are just spread out in the form of a cloud.
That's the electron, located outside the nucleus. Electrons swirl about in a cloud around the nucleus, this cloud is somewhat organized into shells but is impossible to predict the place of one electron at anytime.
This is the particle in an orbital in the space around the atoms nucleus and it is called an electron.
It is somewhat misleading to say that anything orbits the center of an atom. There is an electron cloud that surrounds the center of the atom, but the electrons do not actually orbit, they are just spread out in the form of a cloud.
This is because of the Heisenberg uncertainty principle. It is a part of quantum mechanics. It has to do with an electron having properties of both a particle and and wave. If you only imagine an electron to be a particle, this can be somewhat explained by the process of measuring the position or velocity of the electron. If the data is measured with light, then when a photon hits the electron, it changes the electrons speed and position. We may be able to find one, but in the process, the other will be changed.
The question is somewhat vague. If the question were written as an atom contains seven electrons in the outermost energy level and that outermost shell is a p-shell then the atom is a halogen. If the atom contains seven electrons in the outermost energy level and that outermost shell is a d-shell or f-shell then the atom is a metal.
Remember M.A.L.E and M.I.PMetalAtomsLoseElectronsMetalIonsPositiveHowever, non-metals gain electrons when forming ionic bonds, in order to gain a stable electron configuration. Because they gain electrons, they form negatively charged ions.
... no? The reason for the question mark is that I'm trying to figure out what on Earth you might mean by "new electron". Muons and tau particles are somewhat similar to electrons, but calling them "new electrons" is a bit of a stretch. They've also been known for quite a while; the muon was discovered in 1936 and the tau has been known since the late 1970s.
Every element has an electron configuration based on the number of electrons it has. However, the electron configurations of most elements are at least somewhat unstable. To obtain a more stable configuration, atoms will either share, give, or steal electrons in bonds with other atoms. In short: compounds are generally more stable than single atoms.
They're somewhat of a covalent bond that occurs only between metals. Each atom of that metals essentialy sheds its electrons off and contributes them to one giant 'sea of electrons' that all the other positive metal cations float in to ensure an equal amount of electron sharing throughout the metal.
Na (Atomic number: 11; Electronic configuration: 1s2, 2s2, 2p6, 3s1). Na has 11 electrons distributed in electron shells. This negative charge provided by electrons is countered by 11 protons present in nucleus of Na. The electron in 3s1 is losely held by the positively charged nucleus. When Na loses its outermost electron (3s1), there is an imbalance in the total number of positive charge (provided by protons) and negative charge (provided by electrons). With an increase in positive charge in the ion, the electron charge around the nucleus is drawn closer to it. As a result of this the atomic radius of the Na ion decreases and hence its radius is smaller than that of Na atom.