0
Mathematical Constants
Intriguing, ubiquitous, and at times mysterious, numerical constants set the allowable limits for all universal phenomena. Whether your questions involves π, Avogadro's number, Planck's constant, the atomic mass unit, or any of the other multitudes of immutable numbers used in science, this is the category where they should be asked.
2,332 Questions
What is the value of avogadros number?
The value of Avogadro's number is approximately 6.022 x 10^23, which represents the number of atoms, ions, or molecules in one mole of a substance. This number is a fundamental constant in chemistry and is used to relate mass on an atomic scale to macroscopic quantities of matter.
Who invented the atomic mass unit?
The concept of the atomic mass unit was established by chemist John Dalton in the early 1800s. Dalton introduced the idea of using a standard unit to represent the mass of atoms relative to each other.
Is it true that Avogadro did experiments to determine Avogadro's number?
No, Amadeo Avogadro did not directly determine Avogadro's number. Avogadro's number (6.022 x 10^23) is named in his honor due to his contributions to the development of the concept of the mole and Avogadro's hypothesis, rather than through direct experimental determination.
Is there an atom with an atomic mass of 200?
Yes. There's even a stable atom with an atomic mass of 200 (well, not QUITE 200): Mercury has a stable isotope with a mass of 199.9683. Several other elements (platinum, gold, lead, etc.) have isotopes with atomic mass near 200, but they're all radioactive.
How do you find the atomic mass of lithium?
The atomic mass of lithium is found by adding the mass of its protons and neutrons in its nucleus. It is calculated by taking the weighted average of the isotopes of lithium found in nature, where lithium-6 and lithium-7 are the most abundant isotopes. The atomic mass of lithium is approximately 6.94 atomic mass units.
What is an element atomic mass?
Atomic mass is the number of protons in an atom's nucleus. Since all atoms are, in their natural state, neutral, there are the same number of electrons as protons. Thus, the atomic mass tells you both the number of electrons and protons an atom has.
No, this answer is incorrect. Atomic mass is the number of protons plus neutrons. Only the number of protons is equal to the number of electrons in a neutral atom; so knowing the atomic mass doesn't tell you the number of electrons, because you don't know the combination of protons and neutrons that were added together to get the atomic mass.
Bohr magnetron is equal to Bohr magneton?
The Bohr magneton (μB) is a physical constant representing the magnetic moment of an electron in Bohr's model of the atom. The Bohr magneton is equal to eħ/2mc, where e is the elementary charge, ħ is the reduced Planck constant, and m and c are the electron's mass and speed of light respectively. The term "Bohr magnetron" is a misspelling or mispronunciation of "Bohr magneton."
What is the atomic mass of a atom?
The atomic mass of an atom is the total mass of protons, neutrons, and electrons in the atom, measured in atomic mass units (amu). It is approximately equal to the sum of the number of protons and neutrons in the atom's nucleus.
Calculate the atomic mass of an element?
By taking the wieghted averages of naturally occurring isotopes of that element. :)
Inverse transformation of planck's constant 'h' is and dimensional formula of it?
The inverse transformation of Planck's constant 'h' is called the reduced Planck constant, denoted as 'h-bar' or ħ, and it is equal to h divided by 2π. The dimensional formula of h is energy multiplied by time, or [ML^2T^-1].
Where did Avogadro's number come from?
because it a a supposition of the scientist avagadro and it is not derived from any kind of formula,bczzz it is a absolute value..............and in case someone would derive it,he would be considered GOD.........
Rydberg constant converted to joules?
2.18x10-18 J
This is confusing for students and this book needs to show the derivation. Rydberg's Constant is 1.0974 x 10 7 m-1 which is a distance. Some books say that Rydberg's constant is equal to 2.18 x 10 -18 Joules but this is not correct. They are using (R)times(h)times(c).
What is the average atomic mass of Helium?
The average atomic mass of helium is approximately 4.0026 atomic mass units (amu). This value is a weighted average of the isotopes of helium, primarily consisting of helium-4 with a small contribution from helium-3.
How do you find the atomic mass of the atom?
Add the number of neutrons and protons together to get the atomic mass of an isotope.
The relative atomic mass is the weighted mean of the mass of the naturally occurring isotopes.
Example:
Chlorine has two isotopes
- 37Cl which has 17 protons and 20 neutrons. 17 + 20 = 37 This is 25% of naturally occurring chlorine.
- 35Cl which has 17 protons and 18 neutrons. 17 + 18 = 35 This is 75% of naturally occurring chlorine.
that means the relative atomic mass of chlorine, Ar = 35.5
Carbon's atomic mass is ~12.0107. All of those decimals at the end tell us that there is more than one isotope of carbon. If you round the number, you will find the most common isotope of carbon. (Carbon12)
IUPAC recommend in this case the expression atomic weight, not atomic mass.
The atomic weight of carbon (IUPAC Table, 2009) is [12,0096; 12,0116]. This mean that the atomic weight is variable between the above mentioned limits, depending on the type of the sample.
How does the mass of a protron compare to the mass of the electron?
The mass of a proton is 2000 times the mass of an electron.
Mass of electron: 9.10938 * 10-31 kg
Mass of proton: 1.67262 * 10-27 kg
Mass of neutron: 1.67493 * 10-27 kg
Note that protons and neutrons weigh approximately the same (neutrons are slightly heavier), but electrons are MUCH lighter than both of them.
The MASS of the electron is much smaller than neutrons and protons. It is common, but incorrect, to use mass and weight interchangeably. They are not synonymous.
Who discovered the atomic mass?
Mass is a fundamental concept in physics, roughly corresponding to the intuitive idea of how much matter there is in an object. Mass is a central concept of classical mechanics and related subjects, and there are several definitions of mass within the framework of relativistic kinematics (see mass in special relativity and mass in General Relativity). In the theory of relativity, the quantity invariant mass, which in concept is close to the classical idea of mass, does not vary between single observers in different reference frames.
In everyday usage, mass is more commonly referred to as weight, but in physics and engineering, weight means the strength of the gravitational pull on the object; that is, how heavy it is, measured in units of force. In everyday situations, the weight of an object is proportional to its mass, which usually makes it unproblematic to use the same word for both concepts. However, the distinction between mass and weight becomes important for measurements with a precision better than a few percent (due to slight differences in the strength of the Earth's gravitational field at different places), and for places far from the surface of the Earth, such as in space or on other planets.
Antoine Lavoisier - developed the Law of Conservation of Mass.
Sorry no where does it inidcate who discovered the term "mass".
Hope my info helps
The relative atomic mass of chlorine is 35.5. The two main isotopes are chlorine-35 and chlorine-37.
Atomic mass is the number of protons present in the nucleus or number of electrons revolving around the nucleus in an atom .It is denoted by Z.
Mass number is the sum of number of protons and neutrons present in a nucleus in an atom .It is denoted by A.
The atomic number of tellurium (Te) is 52.
The atomic weight of Te 127.60 grams per mole.
See the Web Links to the left of this answer for a periodic table with more information about this element!
What is the definition of atomic mass number?
Atomic Mass is the sum of the number of protons and neutrons in the atom, plus any additional mass conferred by electrons. (Since electrons are roughly 1/1837th of a proton's mass, this additional mass is minuscule and is only represented in atoms that have atomic numbers at the higher end of the table.) It should be an integer/whole number.
The reason that most elements have a number with decimals for their atomic mass numbers on the Periodic Table is because those numbers average all of the different isotopes of the element in proportion to how common they are. For example, Oxygen has an atomic mass number of 15.999 since the overwhelming majority of oxygens have 8 protons and 8 neutrons for a total atomic mass number of 16, but there are some rare oxygens with 8 protons and 7 neutrons for a total atomic mass number of 15. Once these are averaged, since the 16s are much more common, the resulting number is 15.999.
What is the law of constant mass in chemical changes?
The law of constant mass, also known as the law of conservation of mass, states that the total mass of substances before a chemical reaction is equal to the total mass of the substances after the reaction. In other words, mass cannot be created or destroyed in a chemical reaction, only rearranged. This principle is a fundamental concept in chemistry.
The atomic mass is equal to the number of protons plus neutrons. So if you know the atomic number then you can find out the number of neutrons
Atomic # is the amount of Protons or Electrons
Atomic Mass- Number of protons plus neutrons
Atomic Mass-Atomic Number = Amount of neutrons
What is the difference between average atomic mass and atomic mass?
Average atomic mass is the weighted average mass of all the isotopes of an element, taking into account their natural abundances. Atomic mass refers to the mass of a single atom of a specific isotope of an element.
