Structure of the atom Worksheet-3
A. Atomic Nucleus B. Electron
C. Proton D. Neutron
A. the same physical properties
B. different chemical properties
C. different number of neutrons
D. different atomic numbers
A. 16 B. 8 C. 17 D. 18
A. 2, 8 B. 8, 2, 1 C. 2, 1, 8 D. 2, 8, 1
A. Electron B. Proton C. Neutron
A. Cathode rays travel from cathode towards anode
B. Cathode rays consist of material particles
C. Properties of the cathode rays depend upon the nature of the gas enclosed in the discharge tube
D. Cathode rays are made up of electrons.
A. its charge is always fixed
B. its mass is always fixed
C. it is always present in cathode rays
D. Its charge and mass remain fixed whatever may be the source of its emission.
A. protium B. deuterium C. tritium D. helium
A. protons B. helium atoms
C. helium nuclei D. Lithium nuclei
A. 15,31,15 B. 15,15,16 C. 15, 16, 15 D. 15, 31, 16.
Explanation: Isotopes have same atomic number hence have similar chemical properties. They have different number of neutrons hence their mass number is different.
Explanation: Cl– Ion has 18 electrons (17+1). Hence the number of valence electrons in Cl– ion is 8.
Cl – 2,8,7
Cl– – 2,8,8
Explanation: Electron is known as universal particle.
Explanation: Properties of cathode rays do not depend on the nature of gas enclosed in the discharge tube. Cathode rays consist of stream of negatively charged particles called electrons.
Explanation: He2+ 2 protons and 2 neutrons