Showing posts with label Notes. Show all posts
Showing posts with label Notes. Show all posts
Kidney as osmoregulator and excreatory organ
Kidney is not only excretory organ but it also act as osmoregulator organ .Kidney keep the water concentration in limit.
When the blood is dilute less water is re absorbed from the renal tubule thus large volume of dilute urine is produced.
When blood is too concentrated more water is re absorb from the kidneyll tubule thus amount of concentrated urine is produced
Alkyl Halides introduction Chemistry
Alkyl Halide Introduction:
Alkyl halid are the compounds in which a halogen atom has been substituted for a hydrogen stom in alkanes.They have general formula .
R----X
where R=alkyle group.
and X =F,Cl,Br,I.
The alkyl halide are classified as primery, secondary,or tertiary depending upon wether the halogen atom is attached to a primery ,secondary or tertiary Carbon atom.Alkyle halide are the most useful organic compounds.they frequently used to introduce alkyl groups into organic molecules
Thank you !
Historical background of clissification of lelements (XII Notes)
After Delton Atomic theory the following well known scientists did valuable contribution in the Classification of elements.
Lavoisier.
Dobereiner.
Newland.
Mendeleev.
Moseley.
Lavoisier Classification of elements:
In 1789 Lavoisier classified 25 to 30 elements in two groups"Metals and non metals"
* Metals:
Metals are those elements whose oxide and hydroxide are basic in nature,have low ionization potential,
low electron effinity,low electro negativity and high electro positivity.they are good conductor of electricity.
They Malleable,ductile and have a metallic lustre.Most of the metals are exist in solid state.
*Non Metals:
The non metals are those elements whose oxides and hydroxides are acidic in nature.Non metals have high
ionization potentials,high electron efinity,high electro negativity and low electropositivity.They are bad conductor of Heat and electricity.
This classification failed because there are some elements which are called metalloids.
These elements act as a metal as well as non metals.For example. Graphite and silicon has high melting and boiling point but low densities like non metals.Elements having some properties like metals while some properties like non metals are called metalloids.Thus this classification was rejected.
Lavoisier.
Dobereiner.
Newland.
Mendeleev.
Moseley.
Lavoisier Classification of elements:
In 1789 Lavoisier classified 25 to 30 elements in two groups"Metals and non metals"
* Metals:
Metals are those elements whose oxide and hydroxide are basic in nature,have low ionization potential,
low electron effinity,low electro negativity and high electro positivity.they are good conductor of electricity.
They Malleable,ductile and have a metallic lustre.Most of the metals are exist in solid state.
*Non Metals:
The non metals are those elements whose oxides and hydroxides are acidic in nature.Non metals have high
ionization potentials,high electron efinity,high electro negativity and low electropositivity.They are bad conductor of Heat and electricity.
This classification failed because there are some elements which are called metalloids.
These elements act as a metal as well as non metals.For example. Graphite and silicon has high melting and boiling point but low densities like non metals.Elements having some properties like metals while some properties like non metals are called metalloids.Thus this classification was rejected.
Coulomb Law
Coulomb law definition :
Coulomb law state that the force of attraction or repaltion between two bodies acting on a line joining is.
Coulomb law state that the force of attraction or repaltion between two bodies acting on a line joining is.
- Directly proportional to the product of magnitude of the two charged bodies.
- Is inversely proportional to the distance between them.
What is periodicity in Chemistry and its causes
Periodicity :
"The repetition of Certain properties by the elements at a regular interval is known as periodicity".
Causes of periodicity :
Similarity in the electronic configuration of valence shell of elements is the main cause of periodicity.
Mosely pointed out that !
"The repetition of Certain properties by the elements at a regular interval is known as periodicity".
Causes of periodicity :
Similarity in the electronic configuration of valence shell of elements is the main cause of periodicity.
Mosely pointed out that !
- Atomic number is the fundamental property of the elements.
- Similar elements are repeated at a regular interval When they arranged in the Increasing order of their atomic number.
- It has been found that atom have same number of electron in their valence shell have similar properties.
Atom Radius
So first of all what is atom?
Atom is the smallest particle of matter .Atomic radius:
Atom are so small that cannot be seen by even with a powerful optical microscope.
How ever some techniques are use to measure the distance between to adjacent atoms.
" Thus Half the distance between the centers of adjacent atoms is term as atomic radius".
Physics Electric charge,Definition and their types
Electric charge Definition:
The agent which endowses the property of attraction or repulsion in a body is called charge.OR The tendency of a body to attract or repel any other body is called charge.So charge the intrinsic property of a body due to which it exert force on another body.The charges are of two types .
- Positive charge .
- Negative charge.
In 1600 AD Gilbert showed that some substances when rubbed with each other acquired the property of attracting light bodies. FOR EXAMPLE When glass rod is rubbed with silk both then attract the small pieces of papers. similarly when ebonite rod is rubbed with flannel or animal far both electrify and hence posses the property of attracting small pieces of paper . Franklin gave the name positive charge on glass rod when rubbed with silk and gave the name negative charge on ebonite rod rubbed with flannel .The name given as positive charge or negative charge is merely a convention.
Ordinarily all the objects are electrically neutral because the have equal number of positive and negative charges.the positive charge in an atom is carry by proton present in the nucleus of an atom and the negative charge is carry by the electron revolving around the nucleus .The object can be electrified positive or negative by addition or removal of charges(electrons) .in the process of electrification charge can neither be created but only can transfer from one body to another body.which means that charge is conserved .For example when glass is rubbed with silk some of the negative charge will be transfer from glass to silk.There for the glass rod will be deficit of negative charge and electrified as positively . the silk on the other hand will be an excess of negative charge and it will be electrified as negatively.
The charge in the body exists in the discrete packets rather then continue amount .
This give the quantization of charge. Any charge q is an integral multiple of the minimum elementary charge e.
q = ne Where e is quantum of charge which is very small .
Is experimentally found that .
- The like charges repel each other .
- The unlike charges attract each other .
- Electrostatics .
- Electrodynamics .
Electrostatics :
The branch of electricity which deals with the study of the properties of charge at rest is called electrostatics.Electrodynamics:
The branch of electricity which deals with the study of properties of charges in motion is called electrodynamics.
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