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First ionisation energy: : The energy required to remove 1 mole of electrons from 1 moles of gaseous atoms to form 1 mole of gaseous 1+ ions. E.g. O(g)→ O+ (g) +e-. Ion detection: Fourth stage of TOF spectrometry. The negatively charged plate detects charged particles and a mass spectrum is produced. Ion drift: Third stage of TOF spectrometry.
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The pH of a solution is a measure of the concentration of hydrogen ions in a solution (or the number of hydronium ions). The number of hydrogen ions is a direct measure of how acidic or how basic a solution is. The pH scale is logarithmic and ranges from 0 to 14 (Figure 2). We define pH=7.0 as neutral.
Figure 1.7.1 1.7. 1: An analytical balance makes very sensitive mass measurements in a laboratory, usually in grams. Other common units of mass are the gram and the milligram. A gram is 1/1000th of a kilogram, meaning that there are 1000g 1000 g in 1 kg 1 kg. A milligram is 1/1000th of a gram, so there are 1000mg 1000 mg in 1 g 1 g.
Avogadro’s number (NA): experimentally determined value of the number of entities comprising 1 mole of substance, equal to 6.022×1023mol−1 6.022 × 10 23 mol − 1. formula mass: sum of the average masses for all atoms represented in a chemical formula; for covalent compounds, this is also the molecular mass.
- Molecular Mass Definition
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Molecular mass is a number equal to the sum of the atomic masses of the atoms in a molecule. The molecular mass gives the mass of a molecule relative to that of the 12C atom, which is taken to have a mass of 12. Molecular mass is a dimensionless quantity, but it is given the unit Dalton or atomic mass unitas a means of indicating the mass is relati...
Molecular mass is also called molecular weight. Because the mass is relative to carbon-12, it's more correct to call the value "relative molecular mass". A related term is molar mass, which is the mass of 1 mol of a sample. Molar mass is given in units of grams.
Molecular mass may be calculated bytaking the atomic mass of each element present and multiplying it by the number of atoms of that element in the molecular formula. Then, the number of atoms of each element is added together. For example. to find the molecular mass of methane, CH4, the first step is to look up the atomic masses of carbon C and hyd...
While it's possible to calculate molecular mass for small molecules, it's problematic for polymers and macromolecules because they are so large and may not have a uniform formula throughout their volume. For proteins and polymers, experimental methods may be used to obtain an average molecular mass. Techniques used for this purpose include crystall...
Apr 16, 2018 · Mass number is an integer (whole number) equal to the sum of the number of protons and neutrons of an atomic nucleus. In other words, it is the sum of the number of nucleons in an atom. Mass number is often denoted using a capital letter A. Contrast this with the atomic number, which is simply the number of protons.
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Dec 9, 2023 · The Law of Conservation of Mass is a fundamental concept in chemistry, stating that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. According to the law, the mass of the reactants in a chemical reaction equals the mass of the products. Further, the number and type of atom s in a ...
