Introduction

 Liceo Javier 

English - Advanced Level 

Briana Donis 

Fátima Alaya 

José Rodrigo Morales

 Nicolás Rodriguez 

Fernando Hernández 

Atomic theory and properties of the atomic particles 

 Atoms: Atoms are the building blocks of matter. They are the smallest particles of an element that still have the element's properties. All the atoms of a given element are identical in that they have the same number of protons, one of the building blocks of atoms. They are also different from the atoms of all other elements, as atoms of different elements have different numbers of protons. Atoms are extremely small. The radius of an atom is well under 1 nanometer, which is one-billionth of a meter. Although all atoms are very small, elements vary in the size of their atoms. Although atoms are very tiny, they consist of even smaller particles. Three main types of particles that make up all atoms are protons, neutrons, and electrons

Protons: The detective work that led to the discovery of protons was based on finding the pieces of the puzzle and putting them together in the right way. Electrons were discovered using a cathode ray tube. Electric current flows from the cathode(negative electrode) to the anode (positive electrode). Several experiments have shown that particles are emitted at the cathode and these particles are negatively charged. These experiments demonstrated the existence of electrons. In 1886, Eugene Goldstein (1850-1930) discovered the existence of such positively charged particles. He used a cathode ray tube with a hole in the cathode and observed that the direction of the radiation was opposite to that of the cathode ray. He called these ray channels and showed that they are made up of positively charged particles. Protons are positively charged subatomic particles in all atoms. The mass of protons is approximately 1840 times the mass of electrons. When the electron is removed from the hydrogen atom, the proton is retained. Goldstein observed that the direction of propagation of rays in a cathode ray tube is opposite to that of cathode rays. He showed that these rays are positive particles and called them channel rays. 

Electrons: Electrons are negatively charged subatomic particles. They were discovered by J. J. Thomson by an experiment with a device called cathode ray tube, in 1897. That device was a tube with two metal disks at its two ends- one of them was positively charged, while the other one was negatively charged, both connected to a source of electricity, and an electric current was passed through gases at low pressure. The cathode ray travels from one disk to another. Before Thomson, Sir William Crooke and others did some research on the same topic, the cathode ray. In an effort to learn more about this mysterious ray, Thomson discovered two things, but the one that is important to the discovery of electrons: the cathode ray was made of particles that must have mass. Crooke said it was pressure, but Thomson corrected it saying it was heat. But he wanted to know if those were charged particles, so, using magnets and charged plates, he made a magnetic field, discovering that the cathodic ray would reflect towards. But what is an electron? An electron is a negatively charged subatomic particle, it can be either bound to the nucleus of an atom or free (there is the same number of electrons and protons in an atom). It has a negative charge of -1 and a mass approximately 1/1836 of the mass of a proton.

Neutrons: What is a neutron? A neutron is a particle that is electrically neutral; this was discovered while it was exposed to a magnetic field and later proved to exist by the investigation of the english physicist James Chadwick. It was discovered that the neutrons have the same mass of a proton and it is known that it is the third subatomic particle with a mass equal to a proton. One of the uses of the neutrons is that they are used in the nuclear fission to create new isotopes. By using a collision between a big atom such as uranium and a smaller one as a neutron it gives energy for us to heat water which drives the turbines to make the energy all caused by a chain reaction made from the neutron. As a matter of fact the neutron is the only particle in the structure of the atom of being of neutral charge and is the most close to the nucleus of the atom.

Sources: 

FlexBooks® 2.0. (2019, 16 abril). 4.9 Proton. ck-12. https://flexbooks.ck12.org/cbook/ck-12-chemistry-flexbook-2.0/section/4.9/primary/le sson/protons-chem 

Atom Clipart (#3409542) - PinClipart [Internet]. PinClipart.com. 2018 [cited 2021 Mar 22]. Available from: https://www.pinclipart.com/pindetail/iRwRhmo_atom-clipart/ 

CK-12 Foundation. CK12-Foundation [Internet]. CK-12 Foundation. CK-12 Foundation; 2021 [cited 2021 Mar 22]. Available from: https://flexbooks.ck12.org/cbook/ck-12-middle-school-physical-science-flexbook-2.0/section /3.1/primary/lesson/atoms-ms-ps/?_ga=2.159881343.335843715.1615561171-1833859413.1 615561171&referrer=special 

CK-12 Foundation. (2013, February). Neutron. CK-12 Foundation; CK-12 Foundation. https://www.ck12.org/chemistry/neutron/lesson/Neutrons-CHEM/?referrer=concept_details