The nucleus of an atom is surrounded by an electron cloud that is held in place by an electromagnetic force. The nucleus accounts for significantly more of the atom's total mass than the cloud, although the cloud accounts for a greater volume of the atom.Know More
An atom has three building blocks: protons, neutrons and electrons. The centrally located nucleus is composed of the positively charged protons and the neutral neutrons. These items are bound together by a nuclear force. The number of protons in the nucleus determines what element the atom belongs, commonly referred to as the atomic number. The surrounding electron cloud is entirely composed of negatively charged electrons. Despite the nucleus and surrounding cloud, most of an atom is empty space.
The cloud model was not the first concept. Several models were considered before the cloud was accepted in the 1920s. The earlier models included the Billiard Ball and Plum Pudding models. The Bohr Model was adopted in the twentieth century. In this model, the atom is similar to a solar system.
An electron has a charge of 1.0671 x 10^-19 coulomb. One important property of electrons is the spin. The spin on an electron is a specific rate of 1/2 times a unit of rotation, which may be assigned by the individual doing the measurement.Learn more about Cells
The electron cloud is a way of visualizing the results of mathematical equations used to calculate the position of an electron as it orbits the nucleus of the atom. The area where the cloud is densest describes the most likely location of the electron at a particular point in time.Full Answer >
In any atom with more than two electrons, inner electrons have a repelling effect on outer electrons, reducing the net attraction of the nucleus for the outer electrons. This effect is known as shielding, and it is responsible for many chemical changes in elements near the bottom of the periodic table. Attraction between electrons and protons decreases with distance, and shielding further decreases it but does not remove all attraction.Full Answer >
An electron is a negatively charged subatomic particle that orbits around the nucleus of an atom. The negative charge of the electrons is balanced by the positive charge of the protons in the nucleus. Electrons have a much lower mass than protons.Full Answer >
The core, or dense center of an atom, is called the atom's nucleus. The nucleus contains protons, which have positive charges, and neutrons, which have no charge and are neutral.Full Answer >