Mass number and Atomic number

-
Mass number and Atomic number
The mass number of an element is the total number of protons and neutrons found in the nucleus, in other words the total number of nucleons. The mass number can also be called atomic mass or nucleon number. The mass number of an element is different for every isotope of that element, as isotopes are atoms of an element with the same number of protons but different number of neutrons.
The mass number is different from the atomic number, the atomic number is the number of protons found in the nucleus. The atomic number identifies an element, because no two elements have the same number of protons. On modern periodic tables, elements are classified according to their atomic numbers. So from this we can see that to calculate the number of neutrons in an element, we can simply subtract the atomic number from the mass number;
#neutrons = Mass number - atomic number



Citations:

  • “Log in to Kognity.” Kognity, asoy.kognity.com/study/app/chemistry-sl-fe-2016/atomic-structure/nuclear-atom/atomic-structure/.
  • MonkeySee. “What Is An Atom?” YouTube, YouTube, 13 Nov. 2012, www.youtube.com/watch?v=o-3I1JGW-Ck.

Comments

Post a Comment

Popular posts from this blog

Everyday application of Hess's Law

-
Image
  Everyday application of Hess's Law Burning calories, consuming food, driving home, we all should be familiar with these actions because we do them everyday, but what some of us don't realise is that all these actions related one fundamental law of conservation of energy, Hess's Law.   Hess's Law states that: regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of all changes. [1]   We will further discover how our indrustries, human body and drug production are related to this law and to better understand the science behind it. Industries Today, all our mass and low cost production depends on factories and industries and all these industries require huge amount of energy.   To keep everything the most efficient possible, these industries has to determine the method that is the most effective to produce a product based on the energy needed or released.   For example:  Car companies must determine ho
Read more

Antoine Lavoisier and his contribution to Chemistry

-
Image
The French Bourgeoisie helping out with science: “In performing experiments, it is necessary… that they be simplified as much as possible, and that every circumstance that could complicate the results should be completely removed.” -Antoine Lavoisier Early life and Work: On the 26 of  August 1743, Antoine Lavoisier was born to a wealthy family of nobility and was the son of an attorney at the Parliament of Paris. He  went to school at the College des Quatres Nations, University of Paris at the age of 11 were he studied chemistry, botany, astronomy and mathematics and received a law degree which admitted him the bar. (1). This French nobleman, chemist and biologist is credited for being the first one to put an extensive lists of the elements, helping construct the metric system and reform chemical nomenclature. Lavoisier is also known as the “ father of modern chemistry” (1). Lavoisier who was originally part of the Ferme generale ( most hated components of the F
Read more

Allotrope Blog Post: Graphite

-
Image
Graphite is a naturally occurring allotrope of Carbon. It is classified as the most stable allotrope under STP and its atoms are arranged in a hexagonal structure. Graphite has a very similar composition to that of diamond, but they have completely different properties and structures. Graphite is very soft and is used mainly in manufacturing and for being known as the “lead” in pencils. Graphite itself can come in many different forms. There is flake graphite, chunks of graphite, and it can be trapped in different substances such as marble and metamorphic rocks.  Graphite is an interesting allotrope because of the way the carbon atoms are positioned in the network covalent structure. Graphite is made up of many single layers of Carbon atoms that are off-centered from each other. This is what makes writing with pencils so easy. The graphite layers slide right off of each other because of the weak London Dispersion Forces between layers. This differs from other Carbon allotropes like dia
Read more