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.
What will be the correct sequence after the rearrangement ?
1. In the evening, a dark and menacing storm quickly gathered.
P. Heavy and incessant rain filled the darkness, ancient trees were uprooted an...
In the questions given below, a sentence has been broken down into four fragments labelled (A), (B), (C) and (D) and arranged, not necessarily in the c...
In Each question below has a sentence with five highlighted words that are jumbled. You need to rearrange them in the correct order to make a coherent s...
Which should be the second sentence after rearrangement?
In the questions given below, a sentence has been broken down into four fragments labelled (A), (B), (C) and (D) and arranged, not necessarily in the c...
In each of the questions given below a sentence is given with three words in bold. Choose the option which gives the correct sequence of these words to ...
- Parts of a sentence are given below in jumbled order. Select the option that arranges the parts in the correct sequence to form a meaningful sentence.
... A. incidentally, it is family more often than
B. you learn life’s lessons through hard knocks
C. the disapproving looks of family <...
In Each question below has a sentence with five highlighted words that are jumbled. You need to rearrange them in the correct order to make a coherent s...
Relevant for Exams:
