When we want to find out the valency, we look at electrons only in the outermost shell of the atom. But when we want to know the atomic number or the mass number, we look at the total number of protons and neutrons. 1. Notation of Atom ...
Instead there was an expression on the other’s face oddly reminiscent of a parent about to lecture an offspring on some of the unpleasant facts of life. “Basically,” said Williamson as he gently peeled back a field dressing of a wounded DBLF, “your trouble is that you, and your ...
Atomic number: number of protons in the nucleus of the atom. It defines the chemical properties of the atom. Atomic mass: mass of one mole of atoms, in grams, averaged over all stable isotopes. The atom mass of a pure isotope is equal to the number of protons and neutrons. The unit ...
Distinguish between the following terms: Atomic number and Mass number. How many neutrons does element x have if it's atomic number is 42 and it's mass number is 154? How many neutrons does element X have if its atomic number is 43 and its mass number is 161? A certain atom has an ...
Learn facts about the vanadium element and its discovery. Understand the element's properties, what vanadium is used for, and where it is found on a periodic table. Related to this Question What is the mass number of vanadium? What is the atomic number of iron?
Magnesium Basic Facts Atomic Number:12 Symbol:Mg Atomic Weight:24.305 Discovery:Recognized as an element by Black 1775; Isolated by Sir Humphrey Davy 1808 (England). Magnesium first came into use as magnesium sulfate or Epsom salt. The story goes that in 1618 a farmer in Epsom, England could...
Gallium Basic Facts Atomic Number:31 Symbol:Ga Atomic Weight:69.732 Discovery:Paul-Emile Lecoq de Boisbaudran 1875 (France) Electron Configuration:[Ar] 4s23d104p1 Word Origin:Latin Gallia, France and gallus, a Latin translation of Lecoq, a cock (name of its discoverer was Lecoq de Boisbau...
Fast Facts: Strontium Element Name: Strontium Element Symbol: Sr Atomic Number: 38 Appearance: Silvery-white metal that oxidizes to pale yellow Group: Group 2 (Alkaline Earth Metal) Period: Period 5 Atomic Weight:87.62 Electron Configuration:[Kr] 5s2 ...
Answer to: Two atoms with the same atomic number but different mass numbers are called: a. radioactive b. isotopes c. proteins d. electrons e...
Plutonium Basic Facts Atomic Number: 94 Symbol: Pu Atomic Weight: 244.0642 Discovery: G.T. Seaborg, J.W. Kennedy, E.M. McMillan, A.C. Wohl (1940, United States). The first sample of plutonium was produced by deuteron bombardment of uranium in a cyclotron at the University of Cali...