Structure of atom

Who discovered the electron?

• Rutherford

• John Dalton

• Thomson

• Goldstein

Rutherford’s ‘alpha (α) particles scattering experiment’ resulted in the discovery of

• atomic mass

• proton

• electron

• nucleus in the atom

Which of the following statement is always correct?

• An atom has equal number of electrons and protons.

• An atom has equal number of electrons and neutrons.

• An atom has equal number of protons and neutrons.

• An atom has equal number of electrons, protons and neutrons.

What is the atomic number of aluminium ? Write its electronic Configuration and find out it's valency?

What is the symbol of manganese?

• Mg

• M

• Ma

• Mn

What are valence electrons?

• electrons on the first orbital always

• nucleus

• the number of electrons on the outermost orbital

• the outermost shell

Carbon atomic number is 6. This means that an carbon atom must have

• 6 electrons

• 6 protons

• 6 electrons and protons

• 6 neutrons

99.9% of the atom's mass is located in the

• electrons

• nucleus

• protons

• neutrons

Dalton proved that the true nature of the atom could best be described as resembling "plum pudding."

• True

• False

What types of particles are found in the cloud surrounding the atom's nucleus?

• Positively charged particles and negatively charged particles

• Negatively charged particles only

• Neutral particles and positively charged particles

• Positively charged particles only