Skip to main content

Atoms

Atom

Atoms are the building blocks of matter also known as the smallest unit of matter. The word atom comes from a Greek word meaning invisible. An atom is the smallest particle of the element which can take part in a chemical reaction. The parts of the periodic table are known as elements. It is made up of subatomic particles which are the electron, neutron & proton.

History of Atom

In the Past

  • Long back in India around 500bc an Indian philosopher Maharishi Kanad, explained that if we divide matter, we will get smaller and smaller particles.
  • Ultimately, a time will come will when we shall come to the smallest particle and further division would not be possible. He named these particles as ‘parmanu’.
  • TheIndian philosopher Pakundha Katyayama went a step further and proposed that the particles of matter i.e. parmanu normally exist in a combined form.
  • He also said that the combinations of particles give us various kind of matter.
  • Ancient Greek philosophers Democritus and Leucippus also explained the same theory and called these particles ‘Atom’ meaning invisible.

Dalton's Atomic Theory

John Dalton was born in England 1766 to a poor weaver’s family. He got his early education from his father and village school. He started teaching in the village at the age of 12. Dalton left for Manchester to teach physics, chemistry, and maths in a college in 1793. On 1808, Dalton presented his atomic theory to explain the properties of matter and atoms. 
His theory stated the following:
  • All the matter is made up of very small particles called ‘atoms’.
  • Atoms can neither be created nor destroyed.
  • Atoms cannot be divided.
  • All atoms of a particular element are same in every respect. They have the same mass, size, and chemical properties.
  • Atoms of different elements have different mass, size, and chemical properties.
  • Chemical combinations of atoms form molecules of compounds.
  • The number and kind of atoms in a compound are fixed.
  • Atoms of the same element can combine in more than one ration to form more than one compound.
  • The Dalton theory is based on-
  1. Law of conservation of mass as it states ‘atoms can neither be created nor destroyed’.
  2. Law of constant proportion as it states ‘the number and kind of atoms in a compound is fixed’.

Drawbacks of Dalton's Atomic Theory
  • Dalton’s theory included that atoms couldn’t be divided but under special, atoms can be further divided into smaller particles called electrons, protons, and neutrons.
  • His theory says that all atoms of an element have exactly same mass but atoms of the same element have slightly different masses.
  • His theory also explained that atoms of different elements can have the same mass.

Enjoy your high school with - High School Pedia : www.highschoolpedia.com


Labels:

Comments

Post a Comment

Popular Posts

Piezoelectric Crystal

Piezoelectric Crystal {literally_pressing electricity} Ever wondered what it might be like to live in dark or sleep in a hot summer day without an AC ? Absurd, isn't it ? But with the rate at which we are using our resources, it may not be long before it actually happens. Scientist across the globe are searching for new resources, stocks and technology to prevent the near, unpleasant future of current and the next gen. One of these, an unexploited tech is that of Piezoelectricity. Piezoelectricity is an ability of some special materials (like crystals of quartz, ceramics of lithium niobite, gallium arsenide, zinc oxide) to trigger an electric charge when supposed to mechanical stress. These materials are available in basic instruments that we use in our daily life like microphones, quartz watch, gramophones. All these materials are run by the piezoelectric current. But how does it work? When you apply force (mechanical force) on it, an electric potential, on eit
1 comment
Read more

The Inverse & Reciprocal TRIGONOMETRIC Functions

So, this is my second post on trigonometry. In this post we're gonna cover the reciprocal and the inverse Trigonometric functions. If you haven't seen my first post you should definitely view it as it covers the basics of Trigonometry The Reciprocal Trigonometric Functions The reciprocal Trigonometric function of Sine is Cosecant, of Cosine is Secant & for Tangent it is Cotangent. Cosecant (Csc θ = 1/Sin θ) or (Hypotenuse/Opposite) Secant (Sec θ = 1/Cos θ) or (Hypotenuse/Adjacent) Cotangent (Cot θ = 1/Tan θ) or (Adjacent/Opposite) We can also represent Tan θ in another way. As Tan θ = opposite/adjacent  & Sin θ = opposite/hypotenuse  & Cos θ = adjacent/hypotenuse ∴ Tan θ = Sin θ/Cos θ (The hypotenuses cancel out) As Cot θ = 1/Tan θ  So, we can also represent Cot θ as Cos θ/Sin θ.
2 comments
Read more

High School Pedia

It is an initiative by some students to spread the light of knowledge to everyone and everywhere. It was started in the year 2015 and has grown rapidly in the past few months. By the means of this website, we try to provide information on every topic that we can reach up to. You can find different articles on this website. All these articles are written in simple language so that everyone can understand it and learn from it. We at High School Pedia believe in creative learning and this is the reason why we add our own edited graphical representations in every article. Once a very learned man said, “Knowledge increases by not keeping it to yourself but by sharing it with others”. And we follow the same motto “Share to Learn”. The team of High School Pedia tries its best to provide you with the best and original content. Unlike many other websites, High School Pedia is famous for its original and inspiring content.
6 comments
Read more

Anode Ray Experiment

→Anode ray experiment was conducted by E Goldstein. →These rays are also known as canal rays. →This experiment helped in the discovery of the proton. Apparatus Used A discharge tube  was taken in which there were 2 electrodes i.e. Anode(+ve) and the cathode (-ve). The tube was filled with an inert gas. A perforated or porous cathode was used. A layer of zinc sulphide was placed at the back of the cathode. There was a vacuum pump in the tube. High voltage (5000v-10000v) was allowed to flow through the system. It was observed that when the gas was at 1atm(atmospheric pressure ) no change was seen in the tube.  When the   pressure   was decreased inside the tube, a glow could be seen at the back side of the cathode.
3 comments
Read more

Levitation 2

LEVITATION II To be completely honest I was going to start this with a pun. I did think of one but it doesn’t float… I am sorry I just had to. Anyway, this is the second part to the article on super cool ways of making things levitate. Go check the first part out if you haven’t already. Actually, the first part may have become repulsive with all the magnets and stuff, but I promise this will be more attractive. Get it? No? I’ll stop now. I am just going to jump straight into it. 1.    Electrostatic Levitation I know you are probably sick and tired of magnets but they are the best way you know… This method is somewhat similar. You remember that cool science experiment you did with two straws attracting or repulsing each other based on their charge? So basically using the same principle we can make a charged object levitate. But before you try it, let me tell you it won’t be easy. Even impossible according to our Mr. Earnshaw. He even made a law (the law is
10 comments
Read more

Isotopes, Isobars and Isotones

Isotopes These are elements which have the same atomic number but different atomic mass . They have the same atomic number because the number of protons that are inside their nuclei remains the same. But, they have different atomic mass because the number of neutrons that are also inside their nuclei is different. As the number of protons inside nuclei remains same, therefore the overall charge of the elements also remains same as in isotopes: no of protons = no of electrons . Hence, as isotopes overall charge remains neutral, therefore their chemical properties will also remain identical.   Therefore, Isotopes are chemically same but physically different.
3 comments
Read more

Upcoming Marvel Movies

Hey, guys! Today we are going to talk about the 5 most awaited and upcoming marvel movies. Everyone is eagerly waiting right ?!            1) GUARDIANS OF THE GALAXY vol.2 (2017) Last month marvel shared the first teaser of Guardians of the Galaxy vol. 2   describing it as the official sneak-peak. All five main characters- star lord, gamora, rocket, Drax and 'baby' groot . It is set two months after the first movie where the ravagers find out that peter quill double crossed them about the infinity stone (orb). That's all. Everything else is yet to be discovered.                                                                                                                                                                                
Post a Comment
Read more