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Atomic Mass Name chemical element number 251 Californium 98 252 Einsteinium 99 257 Fermium 100 258 Mendelevium 101 What is the density of cerium? 6.76 g.cm-3 Chemical properties of cerium – Health effects of cerium – Environmental effects of cerium Atomic number 58 Electronegativity according to Pauling 1.1 Density 6.76Read More →

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actinoid element, also called actinide element, any of a series of 15 consecutive chemical elements in the periodic table from actinium to lawrencium (atomic numbers 89–103). As a group, they are significant largely because of their radioactivity. What is the name of 103 elements? Element 103 in the periodic tableRead More →

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Discontinous Spectra 5 illustrates how the light from excited electrons can be diffracted to produce line spectra for the elements of hydrogen, helium, and iron. The specific elements produce wavelengths within the visible spectrum (between 400-700 nm) and can be seen by the naked eye. What is the most accurateRead More →

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Name Calcium Atomic Mass 40.078 atomic mass units Number of Protons 20 Number of Neutrons 20 Number of Electrons 20 How much do electrons weigh? The actual weight of an Electron is 9.05 x 10-28 grams, that’s right, 9.05 times ten to the minus twenty eighth Grams, an incredibly smallRead More →

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102.9055 u Rhodium/Atomic mass What is the scale of atomic weight? Atomic mass is based on a relative scale and the mass of 12C (carbon twelve) is defined as 12 amu; so, this is an exact number. Why do we specify 12C? We do not simply state that the mass ofRead More →

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Chemistry Portal The aufbau principle, from the German Aufbauprinzip (building-up principle), also called the aufbau rule, states that in the ground state of an atom or ion, electrons fill subshells of the lowest available energy, then they fill subshells of higher energy. What is the general rule for filling electronRead More →

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Atomic Number Symbol Name 11 Na Sodium 12 Mg Magnesium 13 Al Aluminum 14 Si Silicon What element has 3 protons 3 electrons? Lithium Atomic Number Name Protons Electrons Lithium 3 3 Beryllium 4 4 Boron 5 5 Carbon 6 6 What is the atomic number of the atom thatRead More →

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ATNO Acronym Definition ATNO All Time New One (amateur radio) ATNO Atomic Number ATNO All Talk, No Action Why do elements have an abbreviation? The periodic table is a classification system for the elements. The symbols are abbreviations of the origins of the word for each element. For example, theRead More →

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Answer: Potassium (K) with an atomic number of 19 has the largest atomic radius. This is because sodium and potassium are elements of group 1. On moving from top to bottom in a group, the atomic radius increases. Does K have a larger atomic radius than CS? Atom size generalRead More →