Density вЂ“ Atomic Mass and Atomic Number Density The Standard English unit is pounds mass per cubic footВ ( lbm/ft 3). The standard SI unit is kilograms per cubic meterВ ( kg/m 3). In words, the density (ПЃ) of a substance is the total mass (m) of that substance divided by the total volume (V) occupied by that substance. It is an intensive property, which is mathematically defined as mass divided by volume: Typical densities of various substances are at atmospheric pressure.ДensityВ is defined as the mass per unit volume. This fact has key implications for the building up of the periodic table of elements. The ordering of the electrons in the ground state of multielectron atoms, starts with the lowest energy state (ground state) and moves progressively from there up the energy scale until each of the atomвЂ™s electrons has been assigned a unique set of quantum numbers. It is the Pauli exclusion principleВ that requires the electrons in an atom to occupy different energy levels instead of them all condensing in the ground state. In the periodic table, the elements are listed in order of increasing atomic number Z. The number of electrons in each elementвЂ™s electron shells, particularly the outermost valence shell, is the primary factor in determining its chemical bonding behavior. The configuration of these electrons follows from the principles of quantum mechanics. The chemical properties of the atomВ are determined by the number of protons, in fact, by number and arrangement of electrons. See also: Atomic Number вЂ“ Does it conserve in a nuclear reaction? Atomic Number and Chemical PropertiesД®very solid, liquid, gas, and plasma is composed of neutral or ionized atoms. It is the electrons that are responsible for the chemical bavavior of atoms, and which identify the various chemical elements. In a neutral atom there are as many electrons as protons moving about nucleus.

The total electrical charge of the nucleus is therefore +Ze, where e (elementary charge) equals to 1,602 x 10 -19В coulombs. Total number of protons in the nucleus is called the atomic numberВ of the atom and is given the symbol Z. The nucleus is composed of protons and neutrons.

The atomВ consist of a small but massive nucleusВ surrounded by a cloud of rapidly moving electrons. PlatinumВ is a chemical element with atomic number 78В which means there are 78 protons and 78 electrons in the atomic structure.

K) 8.8 Thermal ConductivityВ 72 Specific Heat 0.13 Heat of Fusion 19.6 Heat of Vaporization 510 Atomic Number of Platinum.

Platinum вЂ“ Properties Element Platinum Atomic Number 78 Symbol Pt Element Category Transition Metal Phase at STP Solid Atomic Mass 195.078 Density at STP 21.09 Electron Configuration 4f14В 5d9В 6s1 Possible Oxidation States +2,4 Electron Affinity 205.3 Electronegativity 2.28 1st Ionization Energy 9 Year of Discovery 1735 Discoverer Ulloa, Antonio de Thermal properties Melting Point 1772 Boiling Point 3827 Thermal Expansion Вµm/(m

Latinum tungsten