Related Experiment Video

Updated: Dec 26, 2025

Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays
12:48

Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays

Published on: February 19, 2013

11.0K

Absolute Isotopic Abundance Ratios and the Atomic Weight of a Reference Sample of Potassium

E L Garner1, T J Murphy1, J W Gramlich1

  • 1Institute for Materials Research, National Bureau of Standards, Washington, D.C. 20234.

Journal of Research of the National Bureau of Standards. Section A, Physics and Chemistry
|March 19, 2020
PubMed

Keywords:
Absolute ratiosatomic weightisotopic abundancepotassiumreference standard

More Related Videos

Separation of Uranium and Thorium for 230Th-U Dating of Submarine Hydrothermal Sulfides08:43

Separation of Uranium and Thorium for 230Th-U Dating of Submarine Hydrothermal Sulfides

Published on: May 20, 2019

7.0K
High Precision Zinc Isotopic Measurements Applied to Mouse Organs07:04

High Precision Zinc Isotopic Measurements Applied to Mouse Organs

Published on: May 22, 2015

7.7K

Related Concept Videos

Atomic Mass01:52

Atomic Mass

Atoms — and the protons, neutrons, and electrons that compose them — are extremely small. For example, a carbon atom weighs less than 2 × 10−23 g. When describing the properties of tiny objects such as atoms, we use appropriately small units of measure, such as the atomic mass unit (amu). The amu was originally defined based on hydrogen, the lightest element, then later in terms of oxygen. Since 1961, it has been defined with regard to the most abundant isotope of carbon, atoms of which...
69.0K
High-Resolution Mass Spectrometry (HRMS)01:15

High-Resolution Mass Spectrometry (HRMS)

The resolution of a mass spectrometer depends on the efficiency of separating ions with different ion masses. The mass of an atom is approximated to the sum of the masses of protons and neutrons inside, considering the masses of protons and neutrons as equal. However, the masses of the proton (1.6726 × 10−24 g) and neutron (1.6749 × 10−24 g) are not truly equal. There is a minor error in the expression of atomic masses relative to the simplest atom of hydrogen. For...
2.2K
Mass Spectrometry: Isotope Effect01:13

Mass Spectrometry: Isotope Effect

Most elements exist in nature as a mixture of isotopes. The isotopes differ in weight due to their respective number of neutrons. The molecular weight of a molecule is different depending on the specific isotope of its elements involved. As a result, the mass spectrum of the molecule exhibits peaks from the same fragment at multiple positions. The positions of these mass signals depend on the mass differences between isotopes. Furthermore, the intensity of these signals is dependent on the...
3.7K
Radioactive Decay and Radiometric Dating02:48

Radioactive Decay and Radiometric Dating

Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. The number of disintegrations per unit time is called the activity (A), which is directly proportional to the number of nuclei in the sample. The decay constant (λ) is an average probability of decay per nucleus in unit time.
36.7K
Isotopes01:12

Isotopes

Elements have a set number of protons that determines their atomic number (Z). For example, all atoms with eight protons are oxygen; however, the number of neutrons can vary for atoms of the same element. The sum of the number of protons and the number of neutrons is the mass number (A). Atoms with the same atomic number but different mass numbers are called isotopes. Elements can have multiple isotopes, for example, carbon-12, carbon-13, and carbon-14.
An element's atomic mass, or weight,...
63.0K
Atomic Weight01:25

Atomic Weight

Protons and neutrons have approximately the same mass, about 1.67 × 10-24 grams. Scientists arbitrarily define this amount of mass as one atomic mass unit (amu) or one Dalton. Electrons are much smaller in mass than protons, weighing only 9.11 × 10-28 grams, or about 1/1800 of an atomic mass unit. As a result, they do not contribute much to an element's overall atomic mass. This means that, when considering atomic mass, it is customary to ignore the mass of any electrons and...
11.5K