Question
Which isotope was designated as the standard reference for
measuring atomic masses?Solution
Carbon-12 was adopted as the standard reference for atomic mass measurements by the International Union of Pure and Applied Chemistry (IUPAin 1961. The atomic mass unit (amu) is defined as exactly one-twelfth of the mass of a carbon-12 atom. This choice was practical because carbon-12 is both stable and abundant in nature. Carbon-11 is radioactive with a short half-life of about 20 minutes, Carbon-14 is radioactive with a half-life of approximately 5,730 years (used in radiocarbon dating), and Carbon-13 is a stable isotope comprising about 1.1% of natural carbon.
Which of the following plant species is used to produce soft rot resistance through protoplasm fusion?
In dryland agriculture, contingency cropping is due to
This method uses microwaves and silica gel for fast and effective flower dryingÂ
In soil plaque method of soil fertility assessment developed by Winogradsky, which micro organism is studied?
The cultivation of crops with an annual rainfall is more than 1150 mm is called as-
Which chromosome model was proposed by Du Praw on the basis of observation made on Human Chromosome?
Fish which can float in the water column just above the seafloor.
Match List I with List II
List I ...
The study of soil from the stand point of higher plants is known as……………………….
Shallow depth consist of which of the following?
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