Learn Class 8 Science - Some Natural Phenomena

What is Natural Phenomena? In general terms, the natural phenomenon is something that happens by itself. Like it does not need any human interference.

Meaning

  • It means any natural calamity that occurs itself.
  • LIKE: Earthquakes and lightning.

Charged objects

  • Such objects get set by rubbing.

Electrostatic force

  • It is considered as the attraction & repulsion force.
  • And which also includes the charged objects.

Static Electric Charge

  • The charge that does not move.
  • It occurs when two substances come in contact with each other.
  • It depends on two factors, i.e., temperature & humidity.

How do charges get transferred?

Many ways can help to transfer the charges. Such methods are below:

1. Induction:

  • The process results in shifting the electron's position.
  • There is no involvement of physical contact between the objects.

2. Conduction:

  • The transfer of changes happens with the help of a conductor.
  • It occurs when the two objects come in contact.

Electroscope:

  • The concept was given by 'Abraham Bennet' in 1787.
  • The device helps to know whether the object is charged or not.

Structure:

  • The glass jar comes in a vertical brass rod.
  • Rod gets inserted into the jar with the help of cork.
  • Brass rods consist of the brass disc.

Learning Videos for 8th Grade Science - Some Natural Phenomena

Some Natural Phenomena Sample Questions for Class 8

Question 1

Subduction zones occur where
A. oceanic plates move apart.
B. continental plates move apart.
C. an oceanic plate slides underneath a continental plate.
D. a continental plate collides with another continental plate.

Question 2

The image shows the electron-dot diagram for a neutral hydrogen atom.
A. True
B. False

Question 3

The number of valence electrons in an atom is equal to the
A. period number.
B. group number.
C. atomic mass.
D. number of neutrons.

Question 4

The DNA of a eukaryotic cell is mostly located in the
A. proton.
B. electron.
C. nucleus.
D. chloroplast.

Question 5

What is the maximum number of electrons allowed in the second electron shell of an atom?
A. 2
B. 18
C. 6
D. 8