Nucleus The small, dense center of positive

Nucleus the small, dense center of positive charge in an atom. (2.5)... 

Nucleotide a monomer of the nucleic acids composed of a five-carbon sugar, a nitrogen-containing base, and phosphoric acid. (22.6) Nucleus the small, dense center of positive charge in an atom. (2.4) Nuclide the general term applied to each unique atom represented by X, where X is the symbol for a particular element. (19)... 

Nucleus (pi. nuclei) The very small, very dense, positively charged center of an atom containing protons and neutrons as well as other subatomic particles. 

B. Dalton founded modern atomic theory. J.J. Thomson determined that the electron is a subatomic particle but he placed it in the center of the atom. Rutherford discovered that electrons surround a small dense nucleus. Bohr determined that electrons may only occupy discrete positions around the nucleus. 

The structure of the atom and the organization of the periodic table are so inextricably intertwined as to be inseparable. We will examine the structure of the atom first and then see how this structure determines the arrangement and function of the periodic table. The twentieth century was the setting for the unraveling of many secrets of the atom, with the remainder of its secrets on the scientific horizon. At the beginning of the century, the atom was viewed as a small, solid unit. Early in that century, Ernest Rutherford s experiments showed it to be mostly empty space—a truly startling idea said to be the shot heard round the scientific world. His work led to the conclusion that the atom has a dense, positive center, called the nucleus that is quite small compared to the entire atom. An analogy can be drawn about this size comparison If the whole atom were the size of Yankee Stadium, the nucleus would be the size of the baseball held by the pitcher. 

The nucleus is a small, dense, positively charged region in the center of the atom. The nucleus is composed of positively charged protons and uncharged neutrons. 

From his gold-foil experiments, Rutherford realized that the protons must be contained in a small, positively charged region at the center of the atom, which he called the nucleus. He proposed that the electrons in the atom occupy the space surrounding the nucleus through which most of the particles traveled undisturbed. Only the particles that came near this dense, positive center were deflected. If an atom were the size of a football stadium, the nucleus would be about the size of a golf ball placed in the center of the field. 

---