UKPCS Science Chemistry: Compound vs Molecule#3

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you UKPCS Science Chemistry (paper 6). 

What is the difference between a compound and a molecule?

  • A molecule is formed when two or more atoms join together chemically. A compound is a molecule that contains at least two different elements. All compounds are molecules but not all molecules are compounds.
  • Molecular hydrogen (H2), molecular oxygen (O2) and molecular nitrogen (N2) are not compounds because each is composed of a single element. Water (H2O), carbon dioxide (CO2) and methane (CH4) are compounds because each is made from more than one element. The smallest bit of each of these substances would be referred to as a molecule. For example, a single molecule of molecular hydrogen is made from two atoms of hydrogen while a single molecule of water is made from two atoms of hydrogen and one atom of oxygen.

Continue reading “UKPCS Science Chemistry: Compound vs Molecule#3”

UKPCS Science Chemistry: Element, metal & non metal #2

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you UKPCS Science Chemistry (paper 6). 

What is an element? How many elements are there?

  • An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing a single proton and a single electron. If you change the number of protons an atom has, you change the type of element it is.
  • Currently, scientists know of 118 different elements. Some, like gold, silver, copper and carbon, have been known for thousands of years. Others, such as meitnerium, darmstadtium and ununquadium, have only recently been created by scientists. All known elements are arranged on a chart called the Periodic Table of Elements.
  • These elements can further be classified into metals, non-metals and noble gases.Elements to the left of the line are considered metals. Elements just to the right of the line exhibit properties of both metals and non metals and are termed metalloids or semimetals. Elements to the far right of the periodic table are non metals. 

Continue reading “UKPCS Science Chemistry: Element, metal & non metal #2”

UKPCS Science Chemistry: Atomic structure #1

Oracle IAS, the best coaching institute for UPSC/IAS/PCS preparation in Dehradun brings to you UKPCS Science Chemistry (paper 6). 

Atomic structure

All material things are made from atoms. There are just over one hundred different types of atom, called elements. Atoms can join together in millions of different combinations to make all the substances on Earth and beyond.

Continue reading “UKPCS Science Chemistry: Atomic structure #1”