Elements atomic symbols

This Group IIA (or Group 2) element (atomic symbol, Ca atomic number, 20 atomic weight, 40.078 electronic configuration = ls 2s 2p 3s 3p 4s ) loses both As electrons to form a divalent cation of 0.99A ionic radius. Ionic calcium combines readily with oxygen ligands (chiefly water, phosphates, polyphosphates, and carbox-ylates) to form stable metal ion complexes. Ca under-... 

Name of Element Atomic Symbol Physical Appearance of Element ... 

The basic characters from which the notations are constructed comprise the upper-case letters A-Z of the alphabet, the numerals zero (symbolized 0) to nine (0-9), three punctuation marks hyphen (-), ampersand ( ) and oblique (/) and a blank space. Many of the normal atomic symbols such as B, F, P, 1, etc., are also employed unchanged but frequently occurring important elements and groups are assigned a single letter notation (e.g. chlorine sG ... 

The atomic symbol is one or two letters chosen to represent an element ("H" for "hydrogen," etc.). These symbols are used internationally. Typically, a symbol is the truncated name of the element or the truncated Latin name of the element. Click here for... 

Atoms with the same number of protons but a different number of neutrons are called isotopes. To identify an isotope we use the symbol E, where E is the element s atomic symbol, Z is the element s atomic number (which is the number of protons), and A is the element s atomic mass number (which is the sum of the number of protons and neutrons). Although isotopes of a given element have the same chemical properties, their nuclear properties are different. The most important difference between isotopes is their stability. The nuclear configuration of a stable isotope remains constant with time. Unstable isotopes, however, spontaneously disintegrate, emitting radioactive particles as they transform into a more stable form. 

Other methods for indicating or implying the presence of an atom in a nonstandard valence state have been used, especially the use of the prefix hydro e.g. 108). Such methods are sometimes convenient for simple molecules, but they are difficult to apply generally. A more general method that has seen extensive use utilizes the italicized symbol for the element with a superscript Roman numeral to indicate the valence (e.g. 109). This method has been objected to, however, because of ambiguity the superscript Roman number is also used to indicate oxidation number in inorganic compounds, and italicized atomic symbols are customarily used as locants for substituents. The A convention is a modification of the principle of this method, and avoids the objection. It was made a Provisional Recommendation of lUPAC in 1981. 

The components of an alloy are the elements which make it up. In brass, the components are copper and zinc. In monel they are nickel and copper. The components are given the atomic symbols, e.g. Cu, Zn or Ni, Cu. 

Write the atomic symbol for the element whose ion has a — 2 charge, has 20 more neutrons than electrons, and has a mass number of 126. 

TABLE B.2 Element Some Isotopes of Common Elements Atomic number, Symbol Z Mass number, A Abundance, %... 

What will be the systematic name and atomic symbol given to (a) element 126 (b) element 136 (c) element 200 ... 

The language of chemistry is understood better when the symbols of the more common elements are known, such as those shown on the following page. Use of these symbols provides a convenient shorthand method for chemists to represent molecular formulae. In these formulae, the subscript number following the atomic symbol denotes how many atoms of that element are in the molecule, for example, the formula for water is H2O, which means each molecule of water contains two atoms of hydrogen (symbol H) and one atom of oxygen (symbol O). 

The chemical formula for water shows how formulas are constructed. The formula lists the symbols of all elements found in the compound, in this case H (hydrogen) and O (oxygen). A subscript number after an element s symbol denotes how many atoms of that element are present in the molecule. The subscript 2 in the formula for water indicates that each molecule contains two hydrogen atoms. No subscript is used when only one atom is present, as is the case for the oxygen atom in a water molecule. Atoms are indivisible, so molecules always contain whole numbers of atoms. Consequently, the subscripts in chemical formulas of molecular substances are always integers. We explore chemical formulas in greater detail in Chapter 3. 

C02-0091. Each of the elements from chlorine to scandium has a nucleus with A = 40. Write correct atomic symbols for all these nuclei. 

C02-0092. Except for beiyllium, each of the elements with Z values from 1 to 8 has a stable isotope with the same number of protons as neutrons. Write the correct atomic symbols for each of these isotopes. 

Fig. 2.2. The periodic table of chemical elements, displayed in the modem long form. Each element is denoted by its symbol. From U (element atomic number 92) the elements have been...

When we look at a mass spectrum we can observe that a single peak is never isolated but there is one or more small peaks accompanying it to its right (Figure 2.16). These peaks are due to the isotopes of the elements. Isotopes are atoms of the same element that have the same number of protons and electrons but a different number of neutrons. The total number of protons and neutrons constitutes the mass number and it is indicated as a superscript preceding the atomic symbol, i.e. 1H, 12C, 23Na. 

In some cases, it would be convenient to condense the electron configuration. In this condensed form, the electronic configuration of the previous noble gas forms a core represented by the atomic symbol of the element enclosed in brackets (i.e., [He] or [Ne]). The electrons added since the noble gas, follow the noble gas core. For example, cobalt can be represented as an argon core plus the 4s and 3d electrons. Thus, ls22s22p63s23p64s23d7 becomes [Ar]4s23d7. 

Hydrogen The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight 1. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are protons. Besides the common HI isotope, hydrogen exists as the stable isotope deuterium and the unstable, radioactive isotope tritium. [NIH]... 

Make a rough sketch of the periodic table for elements 1 through 18, including the following information group number, period number, atomic number, atomic symbol, and condensed electron configuration. 

Each element has a symbol.There s a particular way of writing what s in a molecule, called a chemical formula.The chemical formula lists all the elements that form each molecule and uses a small number to the bottom right of an element s symbol to stand for the number of atoms of that element. For example, the chemical formula for water is H20.That tells us that a water molecule is made up of two hydrogen ( H and 2 )... 

Jons Jakob Berzelius (1779-1848), a Swedish chemist, is also considered one of the founders of modern chemistry. He prepared, purified, and identified more than 2,000 chemical elements and compounds. He also determined the atomic weight (mass) of several elements and replaced pictures of elements with symbols and numbers, which is the basis of our chemical notations today. 

Examples of isotopes are abundant. The major form of hydrogen is represented as H (or H-1), with one proton H, known as the isotope deuterium or heavy hydrogen, consists of one proton and one neutron (thus an amu of 2) and is the isotope of hydrogen called tritium with an amu of 3. Carbon-12 ( C or C-12) is the most abundant form of carbon, though carbon has several isotopes. One is the C isotope, a radioactive isotope of carbon that is used as a tracer and to determine dates of organic artifacts. Uranium-238 is the radioactive isotope (Note The atomic number is placed as a subscript prefix to the element s symbol—for example, —and the atomic mass number can be written either as a dash and number fol-... 

Name of Element Chemical Symbol Atomic Number Atomic Weight Page... 

Element Atomic mass Symbol Isotopic mass Abundance(%)... 

Note that of all the isotopes of all the elements, only those of hydrogen, and H, also have specific atomic symbols, D and T, with associated names deuterium and tritium. 

Symbol Sb atomic number 51 atomic weight 121.75 Group VA (group 15) element atomic radius 1.41A ionic radius 86 + 0.76A covalent radius 1.21A electronic configuration [Kr] 4di°5s25p3 a metalloid element electronegativity 1.82 (Allred-Rochow type) valence states +5, +3, 0 and -3 isotopes and natural abundance Sb-121 (57.3%), Sb-123 (42.7%)... 

Symbol Be atomic number 4 atomic weight 9.012 a Group IIA (Group 2) metal the lightest alkaline-earth metallic element atomic radius l.OOA ionic radius (Be2+) 0.30A electronic configuration Is22s2 ionization potential, Be 9.32eV, Be + 18.21 eV oxidation state +2... 

Symbol B atomic number 5 atomic weight 10.811 a Group III A (Group 13) metalloid element atomic volume 4.70 cc/g-atom electron affinity 0.277 eV electronic configuration Is22s22pi valence state +3 naturally occurring stable isotopes are B-10 and B-11 and their abundance 19.57% and 80.43%, respectively. 

Symbol Hf atomic number 72 atomic weight 178.49 a Group IV B (Group 4) transition metal element atomic radius 1.442A electron configuration [Xe]4/i45d26s2 common valence +4, also exhibits oxidation states +2 and -i-3 most abundant natural isotope Hf-180 isotopes and their natural abundances Hf-176 (5.21%), Hf-177 (18.56%), Hf-178 (27.10%), Hf-179 (13.75%), Hf-180 (35.22%), artificial isotopes 157, 158, 168, 173, 175, 181-183. 

---