Chemistry is also called as " Central Science " because we require the knowledge of Chemistry in various fields like physics , Biology , Biotechnology , Engineering and many more .
Here are some basic terms to boost your Chemistry concepts.
Matter
Matter is anything having mass and occupy space .
Examples : water , pen , cat , etc .
States of matter
Solid , liquid and gases are the basic states of matter .
Solid state
Solids have fix shape and volume
Examples : Ice , Duster , Board , etc
Liquid state
Liquids have definite volume but no definite shape .
Examples : water , petrol , Diesel , etc .
Gases state
Gases have no definite shape and volume .
Examples : Air , Hydrogen gas , Helium gas , etc . They occupy entire space of the container .
Atom
Atom is the basic unit of matter . All matter is made up of atoms .
Subatomic particles of atom
Atom is made up of subatomic particles,
protons , Neutrons and electrons .
Parts of atom
Atom is divided into two parts :
1.Nucleus
Central core part of atom is called Nucleus . Nucleus consist of protons and Neutrons. Overall charge on nucleus is positive.
Proton is positively charged having mass of 1.672 X 10^-27 Kg and Neutron is neutral in nature carries no charges .Mass of neutron is almost same as mass of proton(I.e 1.674 X 10^-27 Kg) . Whole mass of an atom is concentrated within the nucleus.
Electron
Electron revolve around the nucleus in a particular orbit . Electron is negativity charged. Mass of electron is about 9.1 X 10^-31 Kg and can be neglected in comparison with proton and Neutron .
Mass of proton is equal to 1837 times the mass of electron
Element
Element is a Substance made up of same types of atoms .
Examples : Gold , Silver , Iron
Compound
Compound is Substance made up of more than one types of atoms in a fixed proportion.
Examples : Water(H2O) , Carbon Dioxide(CO2)
Molecule
Molecule is the basic unit of compound.
Molecule is made up of more than one atoms Chemically combined . Atoms can be of same or different types.
Examples : Hydrogen (H2) , Oxygen(O2) , Carbon Dioxide (CO2)
Mixture .
Mixture is Substance made by combining two or more Substance with no fix proportion.
Examples : Sugar in water , sand in water
Types of mixtures
Mixtures can be of two types
1.Homogeneous mixture
This type of mixtures have same composition throughout the mixture . There are present in a single phase(same phase)
Examples : Sugar in water , Salt in water
2.Heterogeneous mixture
This type of mixtures have different composition throughout the mixture . There are present in More than one phase (different phases).
Examples : sand in water , Oil in water
Atomic number (Z)
It is the number of proton in the nucleus of an atom .For a neutral atom , Atomic number is equal to number of protons or number of electrons
Atomic mass number(A)
It is the sum of proton and Neutron present in the nucleus of an atom .
Atomic mass
There is big difference between atomic mass and mass number
Atomic mass is mass of Element with respect to 1/12 the mass of Carbon (C-12).
Here we compare the mass of Element with respect to Carbon(C-12) .
Mole concept
Mole concept is very easy to understand but people get lot's of confusion initially .
Let's see what is mole concept .
Mole is a unit to express large number of atoms , Molecules or particles.
We know that , 12 banana = 1 dozen
In similar way 6.022 X 10^23 atoms , Molecule or particles = 1 Mole of atoms , Molecules or particles
Numerically it is expressed as ,
Number of moles
= Mass of Substance ÷ molar mass of Substance
What is Chemical bond ?
Chemical bond is the force of interaction ( attraction or repulsion ) between two atoms
Chemical bond can be ionic or covalent in nature.
Ionic bonds are formed by lose or gain of electrons between two atoms . Atom which lose electrons carries positive charges (called cations) and other atom which accept electrons carries negative charges ( called anions ) . There is an electrostatic force of attraction between this two ons.
Covalent bond is formed by sharing of electrons between two atoms . Sharing result in overlapping of orbitals and give particular shape to Molecule .
Why Chemical bond forms ?
Noble gases have electronic configuration ns2 np6 (except Helium -1s2) . Each atoms tries to completely fill their outermost orbit by sharing , gaining or losing of electrons, so that they can become as stable as noble gases .
In both cases( Ionic or Covalent Bonds ) , atoms tries to acquire noble gas configuration by losing , gaining and sharing of electrons and become stable Molecule
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