Atoms, Moles, Formulae and Equations

Atom is the smallest particle of an element, which can take part in chemical reaction. Molecule is the smallest particle of an element which can exist on its own and still retain the chemical properties of that element.  Ion is an atom or group of atoms which are either positively or negatively charged due to loss or gain of electrons. First 20 elements Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Flourine Neon Sodium Magnesium Aluminum Silicon Phosphorus Sulphur Chlorine Argon Potassium Calcium Relative atomic mass of an element is the number of times the average mass of one atom of an element is greater than one twelfth of the mass of carbon 12. Relative Molecular mass of a compound is the number of times the average mass of one Molecule of the substance is greater than one-twelfth of the mass of carbon 12. Mole One mole of a substance is the amount containing as many elementary entities as the number of atoms in exactly 12 grams of carbon 12.  Note: Avogadro

Detailed Explanation of Atomic Structure and it's components

  Atomic Structure : This refers to the way an atom is made up of which includes protons, electrons and neutrons Proton: this is the part of an atom that is positively charged. Neutrons; this is the part of an atom that is neutrally charged Electrons: this is the part of an atom that is negatively charged. Below is a simplification of the popular John Dalton's atomic theory which was propounded in the year 1808. Fun question: ask your friend if he/she knows John Dalton . Alright, below is Dalton's atomic Structure theory All elements are made up of small visible particles called atoms. Atoms can neither be created nor destroyed Atoms of a particular element are exactly alike and differ from atoms of all other elements. When atoms combine, they do so in simple ratios. All chemical changes from separation or combination of atoms. But after critical investigation of John Dalton's atomic Structure theory, it was found out that not all of his theories were true, rather this is

11 Separation Techniques Of Mixtures

Types of separation Techniques 1. Seiving: it is a separation Technique which is used to separate solids of different sizes. It is employed in garri processing industries and other industries where seiving is highly needed. 2. Decantation: it is used in separating a mixture containing a liquid and solid particles into two distict layers on standing. 3. Magnetic separation: it is used to separate magnetic substances from non-magnetic ones. It is employed in steel industries. 4. Sublimation: it is the process whereby a substance changes directly from solid to gaseous state without passing through the liquid state . 5. Filtration: it is used to separate soluble particles from liquids. 6. Evaporation: it is used to recover a solid solute from a solution. 7. Separating funnel: it is used to separate two immiscible liquids. 8. Crystallization: it is used to separate salt which decompose on heating, from their solutions. The salt crystals obtained in this way are pure and usually contain

Elements, compounds and Mixtures

An element is a substance, which cannot be split into two or more simple form by any known chemical process. It also means a substance, which cannot be decomposed into simpler substance by ordinary chemical means. Note: There are 109 known elements, 90 occur naturally while the rest are artificial. Elements can be grouped in the periodic table as reactive elements, transition elements, lanthanide elements, actinide, pure metals etc. A compound  is a substance formed when two or more elements are chemically combined together. it is represented by a formula. eg when hydrogen and oxygen is combined in 2:1 respectively. A Mixture is a substance that contains two or more compounds which can be separated by physical means. E.g Dissolution of water.   Features of a Compound A compound can be represented by a definite chemical formula. A compound when once formed is not easy to separate. i.e it's composition is fixed. The constituents element of compounds can only be separated by chemical

What is Matter

Matter Matter is anything that has weight and/or mass and occupies space. examples are stone, plants. States of Matter Matter exists in three physical states like solid, liquid and gas. Solid- it has a definite shape and volume Liquid-it has no definite shape but occupies the volume of the containing vessel. Gas- it has no definite shape but occupies the whole volume of the containing vessel. Properties of Matter  Matter possesses both physical and chemical properties. physical property is associated with physical changes while chemical property is associated with chemical changes. Physical change is one that is easily reversible and no new substance is formed e.g melting of candle wax. Chemical change is one that is not easily reversible and new substance is formed. Eg rusting of iron. Difference between chemical and physical changes Chemical 1. New substance is formed 2. Heat is evolved 3. It is not easily reversible 4. Change in mass Physical 1. No new substance

Introduction to Chemistry

Introduction to Chemistry Before moving on let us firstly look at the definition of chemistry  it is one of the branches of pure science that studies the composition, characteristics and applications of matter. Branches of chemistry Chemistry has many branches but they are basically categorised into three basic headings: These are 1. Organic chemistry: it is a branch of chemistry that deals with carbon and its components 2. Inorganic chemistry: it is a branch of chemistry which studies about inorgan matters like sulphur, etc 3. Physical chemistry: it is a branch of chemistry which studies state and path functions like enthalpy, etc. Reasons why we study chemistry 1. It prepares us to study courses of our interest like engineering, medicine, etc 2. The research and study of chemistry contributed to the invention of a wide range of clothing materials. 3. Chemistry has helped to ensure the availability of medicines.