The question asks for the meaning of the Greek word 'a-tomio' from which the word 'atom' is derived. Understanding the etymology of scientific terms is important in competitive exams as it often provides insight into the historical understanding of concepts.
C) Both a and b. The terms "non-divisible" and "uncuttable" are synonymous in this context and accurately reflect the meaning of the Greek word 'a-tomio' (atomos).
The question asks to identify the scientist who first proposed the atomic theory of matter on a firm scientific basis. This requires knowledge of the history of atomic theory and the contributions of key scientists.
B) John Dalton is widely credited with proposing the first modern atomic theory of matter on a firm scientific basis in the early 19th century. His theory included postulates such as: all matter is composed of extremely small, indivisible particles called atoms; atoms of a given element are identical in mass and properties; atoms of different elements are different in mass and properties; atoms cannot be created or destroyed; and atoms combine in simple whole-number ratios to form compounds. These postulates were based on experimental evidence and helped explain observed chemical laws.
This question tests fundamental knowledge of electrostatics, specifically the interaction between electric charges. The core principle is that charges of the same type (like charges) push each other away, while charges of different types (unlike charges) pull each other together.
A) Attract — This is the correct term to describe the interaction between unlike electric charges. Positive and negative charges are drawn towards each other.
The question asks for the charge of a cathode. To answer this, we need to understand the fundamental definitions of electrodes in electrochemistry, specifically cathodes and anodes, and their associated charges during electrolysis or in galvanic cells.
Therefore, the cathode is negatively charged.
Correct Option: D) Negative
The question asks to identify the scientist who demonstrated the chemical effects of electricity on electrolytes, specifically the liberation and deposition of matter at electrodes. This concept is fundamental to electrochemistry.
Correct Option: B) Michael Faraday is credited with establishing the quantitative relationship between electricity and chemical reactions, known as Faraday's Laws of Electrolysis. His work demonstrated that the amount of chemical change produced by an electric current is proportional to the quantity of electricity passed and the equivalent weight of the substance.
Statement: In cathode ray discharge tube, when sufficiently high voltage is applied across the electrodes, current starts to flow.
Question: The cathode rays start from _____ and move towards the _____
Anode, anode
Cathode, cathode
Cathode, anode
Anode, cathode
The question asks about the origin and direction of cathode rays in a discharge tube. This concept is fundamental to understanding the discovery of electrons and the working principles of early vacuum tubes. The key is to recall the nature of cathode rays (negatively charged particles) and how they interact with electric fields.
C) Cathode, anode. Cathode rays are streams of negatively charged electrons. They are emitted from the negatively charged cathode and are attracted towards the positively charged anode.