Structure of atom class 9

 The nucleons are   

• Protons and electrons   

• Neutrons and electrons  

• Protons and neutrons

• None of these

Tags

NGSS.HS-PS1-8

Which isotope is used in the nuclear power plants to generate electricity?

• Uranium 235

• Iodine 131

• Cobalt 60

• Uranium 238

Tags

NGSS.HS-PS1-8

Who discovered the electron?

• Rutherford

• Chadwick

• Thomson

• Goldstein

What was the source of alpha particles in Rutherford scattering experiment?

• Hydrogen nucleus

• Argon nucleus

• Helium nucleus

• None of these

Tags

NGSS.HS-PS1-8

Why was the Thomson’s Model of an atom failed?

i. It could not explain the screening of negative charges from that of positive

ii. It did not tell about the presence of electrons

iii. It did not give an idea about the discrete energy levels

iv. It explained the atom as a whole to be electrically neutral.

• Only (iii)

• Both (i) & (iii)

• Only (i)

• Only (i)

What property of an element determines its chemical behaviour?

• Size of an element

• Valency of an element

• Molar mass of the element

• None of these

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following does not match the characteristics of an Isotope?

• Isotopes of some elements are radioactive

• Isotopes are the atoms of different elements

• Isotopes differ in number of neutrons

• Isotopes differ in number of neutrons

Which of the two will be chemically more reactive, Sulphur(S) with atomic number 16 or Chlorine (Cl) with atomic number 17?

• Chlorine

• Sulphur

• Both are equally reactive

• Can’t say

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which of the following elements does not exhibit the electrovalencey?

• Sodium

• Calcium

• Carbon

• Chlorine

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Which scientist gave the concept of fixed energy levels around the nucleus?

• Ernest Rutherford

• Neils Bohar

• J.J.Thomsan

• None of these