Element term “element” was first used by Robert Boyle in 1661. An element is a pure substance which cannot be split into two or more simpler substances by any physical or chemical means. It is the simplest form of matter. Copper, iron, gold, hydrogen, oxygen, nitrogen and chlorine are examples of elements. At present, more than 118 elements are known. Out of these 92 are natural elements and others are man made. Hydrogen is an element because it cannot be split into two or more simpler substances by any physical or chemical method. Water is not an element because it can be split into two simpler substances (hydrogen and oxygen) by passing an electric current through it.
Classification of elements:
Elements can be broadly divided into two categories— metals and nonmetals. There is also a third category of elements called metalloids. Such elements have properties lying between those of metals and nonmetals. Boron, silicon and arsenic are examples of metalloids.
Metals have Lustre or Shine:-
They are good conductors of heat and electricity. They are malleable and ductile in the solid state. Most metals are solid at room temperature, except mercury which is a liquid. Examples of metals are sodium, zinc, copper, gold, iron and aluminium.
Nonmetals usually lack lustre and are bad conductors of heat and electricity. They are generally gases, and those that are solid are soft and brittle. Bromine is the only example of a liquid nonmetal. Examples of nonmetals are hydrogen, oxygen, nitrogen, sulphur and phosphorus.
Metalloids have properties intermediate between those of metals and nonmetals. Silicon, boron, arsenic, antimony, bismuth, germanium, etc., are metalloids.
Oxygen is an Element:
No other element has yet been found to be present in oxygen. When pure oxygen is made to react with pure hydrogen, only water is formed. Hence, oxygen is considered to be an element.
An element has only one type of ______________ | |||
Right Option : A | |||
View Explanation |
Which of the following is not considered as pure substance ? | |||
Right Option : D | |||
View Explanation |
Which of the following metal is liquid at room temperature ? | |||
Right Option : C | |||
View Explanation |
It was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.
About Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
Abhyas Methodology is very good. It is based on according to student and each child manages accordingly to its properly. Methodology has improved the abilities of students to shine them in future.
I have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
A marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
Being a parent, I saw my daughter improvement in her studies by seeing a good result in all day to day compititive exam TMO, NSO, IEO etc and as well as studies. I have got a fruitful result from my daughter.
My experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
My experience with Abhyas academy is very good. I did not think that my every subject coming here will be so strong. The main thing is that the online tests had made me learn here more things.
One of the best institutes to develope a child interest in studies.Provides SST and English knowledge also unlike other institutes. Teachers are co operative and friendly online tests andPPT develope practical knowledge also.
It was good as the experience because as we had come here we had been improved in a such envirnment created here.Extra is taught which is beneficial for future.