Select the correct statements from the following :
A. Atoms of all elements are composed of two fundamental particles.
B. The mass of the electron is 9.10939 x 10-31 kg.
C. All the isotopes of a given element same chemical properties.
D. Protons and electrons are collected known as nucleons.
E. Dalton’s atomic theory, regarded atom as an ultimate particle of matter.
Choose the correct answer from the options given below :
C, D and E only
A and E only
B, C and E only
A, B and C only
To determine the correct statements, let's analyze each one:
A. Atoms of all elements are composed of two fundamental particles.
This is incorrect. Atoms are composed of three fundamental particles: protons, neutrons, and electrons. Therefore, statement A is false.
B. The mass of the electron is 9.10939 x 10-31 kg.
This statement is correct. The mass of an electron is indeed approximately 9.10939 x 10-31 kg.
C. All the isotopes of a given element have the same chemical properties.
This statement is correct. Isotopes of an element have the same number of protons and electrons, thus exhibiting identical chemical properties due to having the same electronic configuration.
D. Protons and electrons are collectively known as nucleons.
This statement is incorrect. Nucleons refer to protons and neutrons, not electrons. Electrons are not part of the nucleus.
E. Dalton’s atomic theory regarded the atom as the ultimate particle of matter.
This statement is correct. Dalton's atomic theory regarded an atom as the smallest, indivisible particle of matter.
From the analysis, the correct statements are B, C, and E.
As the question is statement based B, C, and E are the correct statements.
B. The mass of the electron is 9.10939 x 10-31 kg.
C. All the isotopes of a given element same chemical properties.
E. Dalton’s atomic theory, regarded atom as an ultimate particle of matter.
Therefore, the correct option is (C) : B, C and E only
A sphere of radius R is cut from a larger solid sphere of radius 2R as shown in the figure. The ratio of the moment of inertia of the smaller sphere to that of the rest part of the sphere about the Y-axis is : 
A constant voltage of 50 V is maintained between the points A and B of the circuit shown in the figure. The current through the branch CD of the circuit is :
The current passing through the battery in the given circuit, is: 
Given below are two statements:
Statement I: The primary source of energy in an ecosystem is solar energy.
Statement II: The rate of production of organic matter during photosynthesis in an ecosystem is called net primary productivity (NPP).
In light of the above statements, choose the most appropriate answer from the options given below:
The atomic structure of an element refers to the constitution of its nucleus and the arrangement of the electrons around it. Primarily, the atomic structure of matter is made up of protons, electrons and neutrons.
Dalton proposed that every matter is composed of atoms that are indivisible and indestructible.
The following are the postulates of his theory:
Several atomic structures of an element can exist, which differ in the total number of nucleons.These variants of elements having a different nucleon number (also known as the mass number) are called isotopes of the element. Therefore, the isotopes of an element have the same number of protons but differ in the number of neutrons. For example, there exist three known naturally occurring isotopes of hydrogen, namely, protium, deuterium, and tritium.