Free Chemistry Dictionary

Video Example : Elements

Elements

RELATED WORDS

  • metals,
  • Non metals and metalloids
  • Malleable and ductile
  • Sonorous
  • Luster
  • Conducting
  • Poor conductors
  • Solids
  • Liquids
  • Gases

Definition of Elements

An element is the simplest form of matter that cannot be further divided into simpler substances by chemical reactions

More About Elements

  • Elements are the building blocks for all matter
  • Atom is the general term. Everything is made of atoms
  • The term element is used to describe atoms with specific characteristics
  • There are about 120 different elements
  • You are made up of billions and billions of atoms but you probably won't find more than 40 elements (types of atoms) in your body
  • Elements are of three types, metals, non metals and metalloids
  • A chemical element is a pure chemical substance consisting of a single type of atom distinguished by its atomic number, which is the number of protons in its atomic nucleus
  • Familiar examples of elements are carbon, nitrogen, oxygen (non-metals), silicon, arsenic (metalloids), aluminium, iron, copper, gold, mercury, and lead (metals)
  • The properties of metals are
  • Metals show luster
  • Metals are malleable and ductile
  • Metals are sonorous
  • Metals conduct heat and electricity
  • Metals are golden yellow or grey in colour
  • The properties of non metals are
  • Non metals display a variety of colours
  • Non metals are poor conductors of heat and electricity
  • Non metals are not lustrous, sonorous or malleable
  • Few more examples of non metals are iodine, hydrogen, bromine and chlorine
  • The elements having intermediate properties between metals and non metals are metalloids. Ex. Boron, aluminium
  • Number of elements occurring naturally are 100
  • 92 of them are natural and rest are man made
  • Most of the elements are solids
  • Eleven elements are in gaseous state at room temperature
  • Two elements are liquids at room temperature. They are bromine and mercury
  • Elements gallium and cesium become liquids at a temperature slightly above room temperature
  • Most elements are generally stable, a small amount of natural transformation of one element to another also occurs in the decay of radioactive elements as well as other natural nuclear processes

Questions:

Questions. A substance that cannot be broken down into a simpler form by ordinary chemical means is called a(n)

    A. Element
    B. Compound
    C. Mixture
    D. Isotope

Answer: A

Questions. The smallest unit of an element that has all the basic properties of the element is called a (n)

    A, Electron
    B. Atom
    C. Nucleus
    D. Isotope

Answer. B

Questions. Which of the following has no positive or negative charge?

    A. Electron
    B. Proton
    C. Ion
    D. Neutron

Answer. D

Questions . Matter that has a definite shape and is made up of tightly packed particles is classified as a

    A. Solid
    B. Liquid
    C. Gas
    D. Plasma

Answer: A